Page 12 – Sparky's Answers

2000 Toyota Camry A/C Inop, A/C Light Flashes

This 2000 Toyota Camry came in with the complaint that the a/c compressor would cycle on for a second or two, the a/c light would start flashing and the compressor would cycle off. This would happen once during a key cycle. The most common cause of this general complaint would be the a/c magnetic clutch relay. However if the relay was truly at fault the compressor would not engage for a split second and then disengage. It simply would not turn on at all at some point.

In order to test the basic system functions a jumper wire is placed between the two terminals that go to the relay contacts. In this case they are the two larger terminals that run parallel to each other at one end of the relay. Caution: Jumping the wrong terminals can permanently damage the engine computer. With the engine running the a/c compressor should be on and the a/c light should not be flashing. This would indicate that either the relay or the control wire circuit from the computer to the relay is at fault. In this case the light was flashing while the relay was bypassed. The a/c compressor was on, the pressures were normal and the vent temperature was cold. Caution: Do not leave the jumper wire in place for longer than a few minutes even if the previous conditions are met. Even less time if those previous conditions were not met. Operating the compressor in this manner is for test purposes only. Compressor damage will occur if this wire is left in place. The flashing a/c light under this test condition can indicate that there is a problem with the compressor speed sensor.

In testing the compressor speed sensor circuits it is easiest to begin at the compressor harness connector. It is a four cavity square connector with three wires installed. The black/white wire is the command circuit from the relay to the compressor clutch coil. Since the compressor worked when the relay was jumped in the earlier test I knew that it was okay. I moved my focus to the speed sensor circuit. In the next picture I am showing my test leads connected to the speed sensor terminals inside of the connector body at the compressor. They are the two lower ones.

I had a reading of 99.2 ohms. I could not find the specifications for a good sensor but it is within a range that I would expect to see from experience. My assumption at this point was that the sensor was probably not the issue.

I checked for resistance on the wires that attach to the speed sensor. The white/blue wire is routed back to the engine computer and it would be the wire that carries the signal from the compressor speed sensor back to the engine computer. There was a reading of 10.23 k ohms between that terminal and battery ground. Again there was no specifications for this, but it would not be an unexpected reading from a computer circuit.

The brown wire on the other hand showed an open circuit to battery ground. When I looked at the wiring diagram it clearly states that this wire is attached to ground. I checked the brown wire a few inches above the connector and found the ground signal present.

A gentle tug on the wire pulled it out of the connector body. I removed the terminal from the connector body in order to make a repair.

I used this tool to release the plastic clip that held the terminal in place. There was also a white positive assurance clip on the end of the connector that I had to remove first.

I looked through my inventory of connectors and terminals and could not find an exact match. So what I did was used the terminal ears that would normally hold the seal in place and crimped a new wire onto the terminal at that point. Afterwards I slid the seal over the crimped connection and placed it all back into the connector body. I also made sure that the seal was fully inserted into the connector body by gently pushing on it with a pocket screwdriver until it was set. But not so far as to expose the revised crimp location.

I spliced my new wire to the original brown wire at a convenient location.

I rechecked my circuit and now had a proper reading of .5 ohms.

I installed split loom over the harness and secured it as it had originally been.

After reassembling everything, the a/c system now worked correctly.

1994 Chevrolet C1500 Blower Inop/Erratic

This 1994 Chevrolet C1500 came in with the complaint that the blower motor either would not work or work sometimes. A quick check of power and ground at the blower motor itself revealed a lack of ground while the problem was present. With the system on high and the blower motor not working I touched the probe of my test light to the case of the motor indicating a lack of ground.

I know that there is a common issue in a connector behind the glove box so I wanted to drop it down and do a quick inspection and test. After opening the glove box the latches at the sides need to be pulled in so that the glove box will fully open.

Once the glove box dropped all of the way down it was simple enough to lift it off of the hinge pins.

In the next picture you can see the two wire connector that I was looking for. In various year models of Chevrolet and GMC “C” & “K” series trucks and suvs the connector may have more than the two wires shown. There will always be a 12 gauge black and red wire though. If you enlarge the next image you can see a slight brown discoloration on the side of the connector body.

It took a bit of effort to get the connector apart but as you can see it was the source of this problem. There is a secondary fault that could cause this same lack of ground complaint that can be attributed to a loose ground wire connection at the rear of the passenger side cylinder head. Normally this only happens if the engine or head has been removed from the vehicle after it left the factory. Many times the windshield wipers will not work either.

The simple solution for this problem is to just splice the like colored wires together. I happen to have terminals and connector bodies that work well for a more finished repair.

It does not function any better than just splicing the wire connection together but it is a little prettier.

2006 Nissan Sentra A/C Stuck On Heat

This 2006 Nissan Sentra came in with the complaint that the a/c would only blow out hot air and that the driver could not control where the air came out. It was stuck in the defrost position. The fault lies in the plastic housing for the HVAC control head breaking where the cables attach to it. The easy fix is a new control head assembly. The problem is a new control head can range from $300 -$500 usd depending on the year, options and where you purchase it from. A used control head assembly can be found for between $50 – $150 but you stand a good chance of winding up with the same problem. This repair will generally apply to 2000, 2001, 2002, 2003 ,2004, 2005 and 2006 year model Sentra’s.

The first step is to remove the trim panel around the lower half of the HVAC control head assembly. It pulls loose from the dash.

Then the screws for the control head trim panel can be removed.

Now the trim panel can be pulled from the dash. Once removed you will realize that the actual control head is held in place by four more screws and that it will not come out of the dash until some other components are removed.

The upper vent assembly will pull loose from the dash and then the hazard switch can be disconnected.

The radio can then be removed. This one does not have anti theft but if yours does you need to make sure you have the codes to re enter later or the radio may be locked.

Now the four screws that hold the assembly in place can be removed.

Two uppers.

Two lowers.

Looking back into the recesses of the dash you will see where the two controls cables go. You will need to work through this opening and under that dash in order to remove the cables from the door levers.

There will be clips like the one shown below at each end of the two cables for a total of four clips. Be sure not to damage or lose these clips. Take note of all cable positions. Be very sure which cable connects to which door and control knob gear. I look for the scratch marks that are left on the outside of the cable casings. Those marks help in making sure the cables are installed in the original locations.

Sadly I did not get any pictures of just how the plastic is broken and therefore will not allow the clips to stay in place. However what I did was used a small pair of locking pliers and plastic weld epoxy to hold the cables and clamps in place. I started by installing the correct cable and locking clip into the corresponding slots in the control head. I used the locking pliers to hold one side of a clip in place then started applying the epoxy around the clip and cable. I had to make sure the epoxy did not get on the steel cable or onto the locking pliers that I was working with. As one spot cured out I simply re positioned the locking pliers and epoxied another spot into place.

As you could see in the above pictures it took between 4 and 6 steps of clamping and applying epoxy to build up the surfaces so the cables would stay in position. Once everything had cured out it was just a matter off putting it all back together. It is a more difficult to re assemble that it was to take it apart but with a little time and patience it was fixed. With allowing enough time for the epoxy to cure the job should take between 1.5 and 3 hours. The cost was less than $5usd for the epoxy.

2007 Infiniti M35 Changing The Driver’s Side Low Beam Headlight Bulb

This 2007 Infiniti M35 came in with the complaint that the driver’s side low beam headlight did not work. The headlight bulb is a little difficult to get to but not as bad as some others. It does make it much easier if you have a lift available but it can also be done on the ground. The first step is to turn the steering wheel to the full left position. Then from under the vehicle remove the screws that hold the horizontal portion of the inner fender panel in place.

Then remove the push pin retainers along the inside of the wheel well. These are very easy to break and most of the time I find them either already broken or completely missing. There are two parts to the inner fender panel or wheel well liner. We are only concerned with removing the lower/forward portion.

The liner removed and laying on the floor.

Now with the wheel turned to the left and the wheel well liner out of the way the rear of the headlight assembly can be accessed.

The low beam bulb is located behind this cover. It rotates for removal.

With the cover out of the way the bulb base can now be seen. It is important to carefully remove the wiring connector from the bulb first. It was impossible to get a picture of this because I used one hand to hold the bulb in place and the other to pull the wiring connector from the bulb. If you do not do this you may damage the wire spring clip that hold the bulb in place. The other choice would be to undo the clip that holds the bulb in place. Try to wiggle the bulb and harness out of the hole together and then pull the wiring loose from the bulb. I find that method slightly cumbersome.

The wire is off of the bulb and I am carefully pushing in on and moving the retainer wire to one side so that it will unhook from the light assembly.

The rear of the light assembly with the bulb removed.

Pretty clear that this bulb is blown.

2009 Chevrolet Malibu A/C Controls Inop

This 2009 Chevrolet Malibu came in with the complaint that the a/c controls did not work and the whole system was dead. No blower and no compressor engagement. The customer had already bought and installed a new HVAC control head assembly to no avail. Not only did the compressor and blower not work but none of the lights on the control panel would light up either.

As always I started by looking at the system wiring diagram and determined the best place to start testing was at the interior fuse box located behind the center console side panel on the passenger side of the car. I started at the front edge and pulled it loose from the center console and then worked my way rearward.

In the next picture I am pointing to the two fuses that should have had power on them with the ignition on.

Since there was no ignition power on the 10 or 20 amp HVAC fuses above, I moved my attention to the underhood fuse box.

Once the covers were removed I located the position of the run relay fuse #19.

I inspected the fuse and determined that it was blown. I had to remove the translucent cover to expose the fuse element so that you could see it in a picture. I replaced the fuse and turned the system on. Everything lit up and the blower motor came on for a few seconds. The blower motor was noisy and the fuse blew again. Suspecting a shorted blower motor I disconnected the wiring harness to the blower motor and replaced the fuse again. Everything worked except the blower motor. I connected the blower motor while the system was still on and the fuse blew one more time. Keep in mind that I use a special inline fuse holder that uses $0.25 fuses for testing.

To access the blower motor the panel under the passenger side of the dash need to be removed. It just pulls down.

The blower motor does not simply unbolt and remove from the vehicle if it is the original to the car. Instead a utility knife is needed to cut along the seam so that the blower motor assembly can be cut out of the vehicle. You should notice that there are two rings and the knife blade needs to be inserted between the two rings.

This is what the blower motor assembly looks like once it is cut out of the hvac case.

Now that the motor is out the two attaching nuts can be removed and the black plastic housing can be removed from the motor insert. It is very important to not damage or lose that housing as it is needed to install the new motor.

The new motor on the right and the old motor on the left.

This mounting flange and several screws and strips of sealing foam come in the kit.

The foam installed on the new blower motor assembly. The directions did not state in which position to place the foam. The position I chose seemed to work just fine. There are two strips that come in the kit.

It is a little hard to see in the next picture but I did install the flange ring to the blower motor assembly before installing it into the vehicle.

The new assembly installed and working properly.

Two things to note:

Once the flange kit has been installed it will not need to be purchased again if the blower motor ever needs replacing.

The blower speed resistor is just to the left and towards the firewall in the next picture.

2011 Ford Expedition Replacing The Driver’s Side Temperature Door Actuator in Under 2 Hours Part 4

In the process of developing this repair and repair articles I have encountered a fair amount of grief from fellow professional technicians. Originally I posted an abbreviated version on a network that I belong to in hopes of providing a valuable procedure for both my fellow mechanics and their customers. I realize that it is a slightly less than perfect procedure in that one screw was intentionally left out during reassembly. My assumption was that a professional mechanic would understand that the benefits of not having to remove the steering column, dash assembly, hvac case assembly and all of the related parts far outweigh any repercussions of leaving that one screw out. Also that it is a professional alternative to the more invasive manufacturer’s instructions as long as all parties are informed and agree on the procedure.

I also realize that the use of a sponge as a spring/wedge could be interpreted as a bit “hacky”. In my original posting to the professional network I included both topics but probably under explained the research and events that lead me to the use of both tactics. I assumed that the readers would question the screw being left out and I was fully prepared to answer those questions as I have here. The comments about the use of the sponge however were completely unexpected. There were a couple that expressed curiosity. One that stated that it was “a little hacky bro” . Then there was a full out attack on my professionalism as a mechanic and shop owner, my integrity as a human being and aspersions that I might somehow be mentally or physically challenged to the point that I was unable to complete the repair as outlined by the manufacturer.

I found it strange that I went out of my way to investigate an alternative method of replacing a faulty actuator that would normally take about seven hours to replace (possibly five+- depending on how many you have done) and was attacked as a hack for doing so. All without even questioning how much effort and time I put into making sure there would be no repercussions for doing so. We are talking about one of four screws that were used to attach a plastic duct weighing one pound that is ultimately being supported by the vehicle floor board. The stranger thing to me was that no one questioned if there was any way to build a special tool for removing and re installing the screw in question. By the way there is an opportunity to build such a tool if anyone is interested.

Just to clarify a few points:

Although the floor duct could be repaired after it was removed and then re installed I recommend installing a new floor duct as it is quite inexpensive.

Some readers may question the use of a common household sponge …

… for added support of the floor duct. Remember that I had used the sponge previously to check for possible looseness and air leaks and that I only re installed it after the customer had requested it. Even if he had not requested it I do not find it a bad idea to go ahead and use one anyways as it will cause no harm. Also it is very common for foam to be used in manufacturing design to overcome noise and vibration issues.

In the weeks since this repair I have had a chance to collect some additional information to support my method of leaving the one attaching screw out and using the sponge as added support.In the next few pictures are the floor duct, actuator and lower hvac case out of a 1997 Ford F150. Many of you are familiar with this set up you already know that Ford only used two screws to hold that duct in place. I know of no issues involving noises or air leaks in the roughly twenty years since that design.

I was working on this 2006 Nissan Sentra recently and came across this interesting setup. It would seem that the designer has an issue with noise and used of all things a piece of foam for support and or a noise dampener.

Yes, my foam was a common household sponge and not a more closed cell design as Nissan used in this vehicle. However it was more than effective for it’s intended purpose. Just to satisfy the naysayers I might just invest in keeping some more rigid closed cell industrial foam around.

2011 Ford Expedition Replacing The Driver’s Side Temperature Door Actuator in Under 2 Hours Part 3

The other epiphany that I had while thoroughly investigating this process was that I could get to the one hidden screw if the passenger side of the floor duct was gone. Then I thought how could it best be removed without disturbing anything else? I could cut it off with a saw but then what? Figure out a way to patch it back together?

Wait a minute… doesn’t the Ford Motor Company sell parts? I called the local Ford dealership and found that the part lists for about $22 USD and that one could be obtained within two days. I called my customer and informed him of what I had found and offered him these two scenarios:

1. The vehicle would be ready to pick up the next day and the bill would reflect parts plus 7 hours labor. The job would involve removing the front seats, center console, steering column and dash assembly. Evacuate and recover the fluids. Move a few things out of the way (carpet, brackets and etc.) and finally remove the HVAC case assembly. Then the floor duct could be removed and the actuator replaced.

2. The other option would be to wait one extra day, remove the seats, center console and move a few things out of the way (carpet, brackets and etc.). Cut the old floor duct in half. Replace the actuator and install a brand new floor duct minus the one rear screw. I informed him the bill would reflect 3.5 hours labor plus parts. The replacement floor duct lists for about $22 USD.

He asked what would be the detriment of leaving the one screw out? I told him that the corner of the floor duct where the screw was could potentially sag and let a slight amount of air bleed out of the gap instead of being sent to the front and rear floor boards when the system was set to heat. Also that the a noise issue could arise.

His next question was : “Steve, given your years of experience, what would you do if this was your own personal truck?” Being a brutally honest person I told him: “From what I have researched and visually inspected for myself that screw would never be put back in my truck regardless of how I replaced the actuator. That coupled with what I suspected about how the floor duct could be removed, would force me to remove the floor duct in pieces, replace the faulty actuator and install a new floor duct minus that one screw.”

I stated “suspected” because I only had anecdotal information that the floor duct could be removed and installed with no problem. If only that one screw was missing.

I further stated that with his blessing I would like to cut the floor duct and remove it in pieces. Then repair the damaged floor duct and put it back into one rigid piece. This would allow me to test the installation theory. If it worked we would continue with the second option plan. If it did not work I would furnish the new floor duct at my expense and revert back to the option one plan. I also stated that I would also be testing for potential air leaks, noises and vibrations during reassembly. If any were encountered we would also revert back to the option one plan. The only gamble on his part would be the one extra day without the vehicle and possibly saving 3.5 hours of labor costs.

He agreed and I proceeded to cut the floor duct. Cutting the duct was slightly more awkward than I had anticipated because I wound up having to use a hacksaw blade without a handle to cut the duct from the under side. I also had to lift the bottom of the duct off of the floorboard where it rests. I did all of this because I did not want to accidentally cut into the floorboard. Other than that it worked quite well. Access to that one screw was then easy.

I taped the floor duct back together using “Gorilla Tape” to make sure a new floor duct could indeed be re-installed back into the dash and I found that it could be done. I had planned to also use plastic welder to reinforce the repair but the tape made it so rigid that I did not feel the need to. A new duct was ordered and the customer was updated on the repair.

As stated very early on if the floor duct was out of the way the actuator would be almost easy to replace. There are two screws that hold it in place. A ratchet and short 8 mm socket are needed or an 8 mm wrench.

The actuator’s wiring harness connector is at the firewall side of the actuator.

The replacement actuator is Motorcraft part number YH-1933, Ford Motor company part number DL3Z-19E616-A.

The original had a white shaft and the replacement was black. That could have been done because the plastic material was changed or just so it could be easily identified, maybe both. Other considerations that I had while doing this repair was the low cost of the part, the fact that it had already failed after just four years in service and the “Made In China” label. It is very likely that this actuator will fail and need to be replaced several more times in the lifetime of this vehicle. Could you imagine the unneeded stresses and subsequent related parts failures if the complete assembly was removed two to four times over the next 8 to 16 years? I could and that is why I ultimately decided to do it the way that I did.

I encountered a minor problem when installing the new floor duct. There is an extra/added piece of plastic webbing at the rear of the “pocket” where the actuator is located. This was preventing the new floor duct from going past the actuator.

I used a pair of duck bill pliers to remove the bulk of the plastic and then went back and cleaned up the edges with a knife and then a Dremel tool. I would assume the addition of this webbing has been some sort of running production change. In doing this style of repair on a later model truck one might encounter that same webbing and it could make it more difficult to remove the original floor duct. I compared to two parts extensively and the only reason that I could come up with for the additional webbing was obsessive designing or possibly to prevent the actuator harness from being disconnected/damaged by accident or on purpose before the main HVAC assembly is installed in the vehicle.

The new floor duct has to be installed at a slight angle and then rolled into position.

There is also this white aspirator tube that has to be dealt with during removal and installation of the floor duct.

After the new floor duct was installed and the truck was going back together. I temporarily installed the center console and tested the system out. This was without installing the other brackets, trim panels or fully putting the carpet back into place. The system is partially inoperative with the rear controls disconnected. I directed the air flow to the floor vents and checked for noises (whistles, hisses or vibrations) at various blower speeds and temperature settings and none were present. I also placed my fingers between the driver’s and passenger side of the floor duct and the firewall padding to feel for any air movement. Granted I could not reach the suspect corner but no air movement was felt and yes I took my gloves off to do that.

Since I could not fully reach the corner where the missing screw would have been I decided to introduce a foreign object behind it that would make an audible difference in the tone of the air flow if it moved past an air leak. I used a folded piece of paper and a piece of light cardboard and no leak could be detected. My last choice of material turned out to be a common sponge in a plastic wrapper. I slid it in from the driver’s side and pushed it across to the passenger side going right past the missing screw location. I did this several times and there were absolutely no audible changes. I did notice a very slight movement in the floor duct when the sponge was inserted and moved from one side to the other. I did not know for sure if it was lifting a low corner or just flexing the plastic in general. I strongly suspected that there was just general deflection since the angles at the junction point to the main HVAC case and the thickness of the material make that area quite rigid.

The customer shows up as I am finishing the truck and picking up my tools. I was joking with him about finding missing objects under the seats and center console including his eyeglasses and lipstick. Not his color he says so we suspect it was his wife’s. He asked where in the world I found the sponge that was also laying on the seat? I explained to him how I had used it to test for air leaks and he thought that was very interesting. We then talked about just leaving it in there just in case the plastic wanted to shift and a noise might develop. He asked if the sponge would fall out and I explained that due to the compression of the sponge and the resultant spring action, that the sponge would stay in place. I put it back in at his request and feel absolutely no remorse and not one bit “hacky” for doing so!!!

More about my last comment in the follow up to this repair.

Part 1 of 4.

Part 2 of 4.

2011 Ford Expedition Replacing The Driver’s Side Temperature Door Actuator in Under 2 Hours Part 2

Now that the seats and center console are out of the way it is time to start removing the metal brackets.There is a bracket that holds the wiring harness to the main frame. In order to get the wiring out of the way the connector body from the front harness needs to be removed from the bracket. There is a plastic clip that has to be released and then the connector body will slide up and off of the bracket. Remove the nut and bolt that hold the small bracket to the main metal frame. Then move the bracket with the rear harness still attached towards the rear of the vehicle. Also while in that area the two screws at the front of the main metal frame can be removed. Those two screws attach the bottom of the dash carrier unit to the center console bracket.

Now the two rear bolts can be removed and the bracket can be placed out of the way. The carpet can now be rolled towards the rear of the vehicle. You should notice that the carpet is not shown in the next few pictures. That is because I got ahead of myself in trying to take pictures for documentation. The vast majority of the pictures that I take are during re-assembly.

Here I am showing the black trim panel that attaches to the floor duct and covers the wiring harness and brackets. By the way the wiring harness should be under the carpet. As stated earlier I was doing a lot of inspection and testing during this repair so the position of the carpet and some of the parts are not always the same as one would see during disassembly.

The passenger side of the trim panel with the push pin retainer can be seen in the next two pictures. There are two push pin retainers on the driver’s side of the floor vent.

With the trim panel and the carpeting out of the way the last of the metal bracketry can be removed.

Now the under carpet rear floor duct can be removed. There are two push pin retainers that have to be pulled out. One on the passenger side and one on the driver’s side.

Now the main floor duct can be seen.

If you look carefully towards the right side of the floor duct, sandwiched between the HVAC case and the floor duct is the driver’s side temperature/blend door actuator.

The problem here is deciding how to proceed. I did a lot of research to find the best approach to removing the floor duct to gain access to the actuator. The “tricks” that I found were:

1. Use a pry bar to crush the floor duct down. Remove the far passenger side screw with a wrench. Follow that with using another pry bar to break off the remaining actuator mounting tab. Remove the actuator and re install it with only one mounting screw. Although the task would be done and the actuator would be replaced, I did not feel it was suitable for myself or my customer and he agreed.

2. Remove all three mounting screws that are accessible. Then pull on the floor duct to break the loop on the bolt hole so that the floor duct could be pulled out. I have done dash work extensively for the past 30+ years. I examined the material around the screw holes that were accessible and tugged around to get a feel if this option was viable and for me it was not. I strongly felt that the wrong plastic parts would break turning this job into a nightmare.

3. Loosen the dash assembly and the HVAC case so that one’s hands could fit in between the HVAC case and the firewall to reach the one hidden screw. I examined the fastener lengths and gauged the amount of room that might be gained and realized this would not work for my large hands and forearms.

4. Remove the dash, steering column and HVAC case according to the manufacturer’s instructions. The whole procedure is supposed to take about 7 hours. Five to six more from this point of disassembly. The refrigerant has to be recovered and the cooling system drained as well.

I have taken hundreds of dashes and HVAC cases out in my career and will likely take out many more. I understand the pitfalls that go along with doing it also. Most of the parts are made from plastic and they all become very brittle as they age. The heater and evaporator cores are made of soft metals that over time will harden and they too become brittle and subject to fracture. The circuit boards inside of all of the modules weaken. The wiring harnesses almost never lay back in the exact same places for a multitude of reasons.

All in all it can be quite a traumatic experience for all of the dash parts on any vehicle (new or old) to be removed and re-installed. All of this experience along with the anecdotal writings of others lead me to believe that if that floor duct could be removed and re-installed without removing the HVAC case and related parts the truck, my customer and myself would be much better off in the end. There were only two snags:

1. How to remove the floor duct without damaging anything?

2. What ill effects would come from leaving out the one screw that was hidden behind the floor duct? The one that was preventing the floor duct’s removal.

I contacted my customer and got his okay to test various theories. The first thing that I did was remove each of the three visible and accessible screws one at a time. Each time I removed and tested the effects of one screw being missing, I re-installed it and moved to the next screw on my list. There were no visible or audible side effects present with having any one screw missing. I repeated the tests with two screws and then three screws left out. Still no side effects. You can even see in the next picture with all screws still in place the floor duct actually rests on the floor board in some places. Also remember that there is another piece of duct work that goes over the foam gasket (Kind of reminds you of a sponge doesn’t it?) that is touching the floor.

I was looking at all of these components and thinking about why there were any screws at all holding the floor duct in place. A simple foam gasket and the assembled tolerances would be more than adequate to seal the seam between the main HVAC case and the floor duct and also prevent vibrations and noises. I have seen that same process used thousands of times while working on dashes for over 30 years.

Then it dawned on me. It was the assembly line process that dictated that the floor duct be attached to the main HVAC case. The case is not made on the main assembly line. It may not even be made in the same factory. This means that the completed assembly has to be packaged and transported to the main assembly line. It has to be unpackaged and attached to an assembly line arm. Then the whole thing has to be placed into the truck on the assembly line. A good bit of the time it will be suspended in the air with nothing under it for support. That means that the floor duct has to be attached to the main case. The manufacturer would not spend the extra time or money to install the case and then attach the floor duct to it, in the vehicle. Thank goodness they did not decide to attach it with glue. That would mean that the entire HVAC case assembly would likely have to be replaced if that actuator failed. Of course that would fit in fine with some who recommend replacing the whole assembly rather than fixing it anyways.

My conclusion was that although it may be less than perfect leaving that one screw out would have no ill effects on the vehicle or the customer. Keep in mind that I absolutely do not condone leaving screws out as a regular course of business but sometimes it just makes more sense. Especially when it has been thoroughly thought out and approved of by all parties concerned.

Okay now that I have addressed the concern of leaving the one screw out all I have to do is figure out how to remove the floor duct with that one screw still in place.

Part 1 of 4.

Part 3 of 4.

2011 Ford Expedition Replacing The Driver’s Side Temperature Door Actuator in Under 2 Hours Part 1

This 2011 Ford Expedition came in with the complaint that the driver’s side vents were stuck on heat. Since this truck has rear floor vents under the seats as shown below, the seats have to be removed from the vehicle.

The plastic trim covers unsnap from the seat brackets to reveal the attaching bolts. The seats need to be positioned fully forward to remove rear the bolts.

Then the seats need to be moved fully to the rear to remove the front bolts. The trim cover in the front has already been removed in the next picture. Also there is only one and it is over the outermost bracket and bolt. After all of the bolts are removed the seat should be moved one more time to center the seat over the tracks. Then the seat can be tilted back to access the wiring harness so that it can be disconnected. The yellow connector bodies are for the seat airbags and the manufacturers procedures should be followed before disconnecting and reconnecting those harnesses.

Once the wiring harness is fully disconnected, inch the seat assembly forward enough so that the seat back can be rotated towards the door opening. Doing this allows for the seat to be picked up by the backrest and rear seat cushion area. This coupled with the seat track’s centered position makes it less likely to damage any trim panels upon removing the seat,. I removed the sill plate and laid a fender cover over the carpet. I also had previously rolled the window down and hung a fender cover over the interior door panel to help prevent damage.

Now that the seats are removed the attaching side screws for the center console can be removed. The forward screws have cover plates over them that have to first be removed. I had already removed them before taking this picture.

The center console’s upper trim plate has to be removed. First lift the insert in the front storage tray to expose the 7 mm headed screw.

Of course the next step is to remove that screw.

This step is one of choice and until I get to do this again I will not be sure which is best. I knew the trim ring around the shifter assembly needed to come off but I was not sure how. In the end I used a wide plastic pry bar to lift up on the ring near the points of resistance and then used a small screw driver to move the tabs away from the shifter body. I worked my way around until all four clips were released.

I then used the same wide bladed plastic pry bar to lift the trim panel and released the spring clip. The spring clips are very tight and there are quite a few around the exterior edge. I started at the driver’s side rear edge and then the passenger side rear edge. Going from one side to the other I worked my way to the front.

I have read about others just concentrating on lifting the main panel out and the trim ring will come with it. Honestly it all felt like it was going to break to me so I was just going with experience and trying not to break anything.

Once all of the spring clips were free I moved the shifter handle back and lifted the panel up and towards the rear of the truck.

Now the main center console’s two forward screws could be removed.

The shifter cable and the harness junction blocks are still holding the center console in the truck.

There is a locking tab that needs to be released before the cable can be slid up and out of the housing.

I then removed the four bolts that hold the shifter to the console.

Then disconnected the wiring harness connector.

I did not feel that I could get the correct angle on the shifter cable to release it without breaking something so I released the plastic clips that hold the top trim panel in place first.

Then I could get a suitable tool in there to detach the cable end from the ball.

Now that the shifter assembly is out of the way I could turn my attention to the harness connectors. The two large connector separate by fully loosening the center attaching bolts.

Then the SRS wire can be disconnected. Again use the manufacturers guidelines before working with the SRS system.

This is what you have left after the center console’s main body is removed.

Part 2 of 4.

Part 3 of 4.

GM “C/K” & “S/T” Vehicles, HVAC Recalibration Using a Tech 2 Scan Tool

It Recently came to my attention that some of my readers wanted to see how to perform an actuator recalibration using a Tech 2 scan tool. The pictures are dark and they are best viewed in low light conditions.

Connect the scan tool to the DLC and turn the ignition on.

After entering the year,make, model and etc. information this screen will appear. Select “Body” at this time.

This particular vehicle has dual zone auto a/c controls.

Also the uplevel radio.

Heating and Air Conditioning.

Special Functions

HVAC Actuator Recal.

Lastly select Reset using the soft buttons.

Now place your hands in your pockets and touch nothing in the vehicle. After one to two minutes have passed and you can hear no more movement/changes in the dash, turn the ignition off for at least ten seconds but no more than thirty seconds. Turn the ignition back on and check the HVAC operation.

The recalibration sequence starts when you command Reset and does not end until the key is cycled back on.

If an actuator fails to recalibrate and the process stops. So if the first actuator in the sequence fails the other actuators may fail to be recalibrated properly.

Systems with auto controls will default to 74°F when reset is commanded.

On manual systems I set the blower control on speed 3 before beginning. This allows me to hear and feel the door movements.