2006 Buick Lucerne, A/C Loses Refrigerant Charge

This 2006 Buick Lucerne came in with very poor a/c performance. A quick check revealed a low system charge and a little looking around and I found the telltale green dye.

A little bit better view. I like how the camera flash makes it glow similar to the UV lights we use in the shop.

The fitting seals need to be changed and the upper one it pretty easy since the bolt comes through from the engine side. The other one is not quite so easy. The nut has to come off from the grill side of the fitting. Start by removing the top cover. It is held in place by push pin retainers. Push the center in slightly until it clicks. Then lift the whole push pin assembly from the panel. Once all of the pins are removed, the panel will lift off.

I removed the top screws that hold the headlight assembly in place. I then found another one located at the bottom of the hole. I removed it. The headlight was still held firmly in place. I guess you are supposed to remove the whole front fascia to get the headlight out of the way.

I did not want to do all of that so I decided to use a short 13 mm wrench to see if I could work down in the hole. I could and did but could not take a picture with my hand down in there.

It only took a few short wrench movements to loosen the nut enough to finish taking off with my finger tips.

Once all of the fasteners were loose it was just a matter of maneuvering the lines around enough to clean them and install new sealing washers.

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Time to vacuum it down and recharge the system. As a side not this vehicle had the condenser changed about 18 months ago when it was in a body shop for a front end  repair.

After the system was recharged I used a degreaser and cleaned up all of the oil and dye residue.

1994 Ford F150, No Run Condition, Burnt Smell In Cab

This 1994 Ford F150 was towed in with a no run condition. The customer told me that he was driving along and started smelling something burning. The next thing he knew there was smoke under the driver’s side of the dash and the engine stopped running. I have seen this before, so I stuck my head under the dash near the parking brake assembly and checked for the burnt smell. Sure enough, the sweet smell of burnt electronics. the computer had expired.

The computer is a little difficult to remove. First loosen the 10 mm headed bolt on the center of the PCM harness connector.

Next I removed the upper and lower 11 mm nuts that hold the retaining plate in place. Notice I used a swivel and long extension.

The cavity with the PCM removed. It is not quite as easy as just pulling the PCM out though.

The inner fender panel has to be loosened up so that the plastic panel can be flexed enough with a pry bar to allow the PCM to be removed. There are several screws along the curved edge of the plastic panel that have to be removed and one underneath. After that a pry bar can be inserted between the plastic inner panel and the steel fender edge. I did not have a good feeling about the chrome trim

So I removed the phillips headed screws that held that on.

And removed the trim from the fender.

I would recommend taking you time and being careful so that you do not damage the paint or the fender with careless or excessive force. Free at last.

Now with the PCM out of the truck, I could really smell the burnt electronics emanating from the unit.

There are two torx screw that hold the sheet metal cover in place. One on either side.

I think it is safe to say this PCM is toast.

I have seen about a dozen of these over the past 4 or 5 years and to my knowledge it is an internal failure. I have seen nothing in the engine or transmission system to be causing this kind of failure.

1990 Chevrolet K1500 Pickup, Multiple Electrical Problems

This 1990 Chevrolet K1500 Pickup came in with multiple complaints. The headlights and park lights did not work. The dome lights did not work and the horn did not work. The vehicle owner had already found out that there were three dead fuses in the interior fuse box. It is kind of strange saying that as this truck only has one fuse box. It seems everything I now work on has multiple fuse boxes.

I pulled the dash cover to check for power at the headlight switch and found none.  There are four torx drive screws. One in each corner. Then tilt the steering column fully down and place the shifter in D1 position. This allows enough room the maneuver the trim panel away from the dash and unplug the harness connectors for the light switches.

The red and orange wires should have had constant battery power present.

I also confirmed that courtesy and park light fuses were dead also.

I inspected the fusible links under the hood on the passenger side firewall. They were all okay.

A little bit clearer view of the fuse box.

This one took quite a while to find the answer because the wiring diagrams were not accurate. The diagrams showed the fuses getting power from the same source as the ignition switch. Not true in this case. The thing that got me looking beyond the wiring diagram was the fact that the stoplights worked. According to the diagrams they shouldn’t. Realizing there was an undocumented power supply, I started looking at wire diameters and insulation finish. Of course I had to open the harness up under the dash to do this.  None of the suspected wires matched in appearance. I started over at the fusible links. All were okay. I did however notice the insulation finish and found another direction to go in literally. This one red wire went into the passenger end of the firewall. I looked under the dash and could not find it. I removed the glove box liner. There are four screws that hold it in place.  there it was, a single red wire with an in line connector. Power on one side.

There it is, a single red wire with an in line connector. Power on one side.

No power on the other side.

A burnt in line harness connector.

I cut it out and replaced it with a splicing connector.

A quick reassuring check for power.

Heat shrink tubing in place to insulate the connector.

Now there is power at the headlight switch connector.

Also at the fuses in the fuse box.

Now for the reason  the connector burnt out. The red wire in the picture below feeds power to a radio amplifier. That amplifier overloaded the circuit and caused the in line connector to fail. In all of the years I worked on these trucks regularly, I never saw that connector burnt out. Now I have, but this one is now done.

The amplifier.

1997 GMC Savana Van, Changing The Blower Resistor

This 1997 GMC Savana van has a problem with the blower speed dropping without the switch being moved. The resistor as you can see in the picture below is quite easy to get to. It is under the hood on the passenger side of the vehicle.

If you would click on the picture below to enlarge it, you will see a slight discoloration of the third terminal from the right in the picture below. That terminal is in the “C” cavity of the harness connector and the wire color is black. This is the main ground for both the blower motor and the high blower relay that is within the blower resistor assembly.  You should also be able to see that terminal “A”, red wire at the far right is also slightly open. Both of these terminals are in the process of failing. When a condition like this is encountered, the blower resistor and the harness connector should be replaced at the same time. The driver should also be informed to not use the high blower speed for more than about thirty minutes at a time, with at least a five to ten minute rest before going back to the high blower position. The evaporator core needs to be checked for debris that may be restricting air flow. The van needs to be checked to make sure that all window and door seals are good and in place.

If you need these parts please click here, to order.

Removing the blower resistor from this point is pretty simple. Push in the locking tab at the blower motor harness connector. Then pull the wiring from the blower motor.

The wires are secured behind a plastic hook on the heater-a/c case.

A closer look at the hook. It seems kind of like misplaced priorities by the design team. Their time could have been better spent designing a heavier connector or better body seals. I say body seals because if the van was sealed better the driver might decide to turn the blower speed down and not just leave it on high all of the time.

Enough of the belly aching. There are two 5.5 mm headed screws that hold the resistor in place.

The new resistor is slightly larger than the original and the hole has to be enlarged as a result.  There should be a template in the box with the new resistor. The customer was not ready to do this repair so I cannot show how to cut the box. It can be doe with a good utility knife or a hacksaw blade. There are power tools that will work as well. A couple of things to keep in mind while doing this modification.

Do not damage anything inside the case. Can we say Evaporator Core?

If you use a hacksaw blade or power tool, also us a shop vacuum while cutting to remove the cuttings before they fall into the case. Make sure the interior is clean before installing the new resistor. Dirt and leaf build up can cause the blower motor to draw too many amps while it is working and this can cause early failure of the new part.

Make sure the enlarged opening will allow the resistor to be installed properly but also make sure that you do not cut beyond the sealing edge of the new resistor, or you will have an air leak and possible water intrusion.

The “M Van ” template is for Astro and Safari Vans. The “GMT560/610” template is for Express and Savana vans.

1998 Chevrolet K1500, Right Rear Turn Signal Erratic

Well, I got to see something new today. The customer brought this 1998 Chevy K1500 in with the complaint that the right rear turn signals would not work with the park lights on. I thought no big deal, the right rear socket board has weak internal ground. Seen it a hundred times if I have seen it once. Went and got a new board and three new bulbs out of the cabinet. Installed the new assembly and checked to make sure I had corrected the problem. No such luck. Well it has to be a weak ground signal to the board. I will just add and extra ground. Problem solved. Wrong. I have to admit this one had me stumped for a few minutes. I racked the truck up so that I could check the wiring underneath. I started looking at the wiring around the back of the truck and noticed that the trailer socket mounting bracket was bent. No real big deal but I saw that the wiring would unplug, so I though I would unplug it, to check the signals at this location.

When I grabbed the wiring to disconnect it, I noticed right away that it was warm. Warm wires? There should be no stinking warm wires at this connector.  Let’s see what is happening inside. Notice the melted plastic just to the right of the right turn signal terminal in the trailer socket.

A little clearer view.  Notice the red dots to the right side of the socket assembly. They are built in LED test lights for the different circuits.  They will illuminate any time a particular signal is active.

Apparently they will also kill a signal when shorted internally. If you look closely you will notice that I disconnected a harness connector behind all of this to remove the shorted socket from the circuit. The customer decided not to replace the socket assembly at this time.

2005 GMC Sierra, Air Blows Only From Defroster Vents

This 2005 GMC Sierra came in with the complaint that the air will only flow from the defroster vents, regardless of where it is commanded to. This Sierra has auto a/c controls and no floor mounted center console.

Of course the customer brought the truck in, knowing that I had to lay under the driver’s side of the dash and did not think to vacuum the floor board.

I checked the codes and sure enough there was a code B0263 stored in the HVAC module. Your scan tool has to be able to go into the body systems to see this information. A plain OBD2 scanner just won’t do the job. This repair is so common that you can diagnose it by symptom if you have to. The most common symptom of course is lack of control over the vent output position and normally it will be stuck in the defroster only position. If it is not currently stuck in the defroster position but you are changing the actuator anyways. make sure that you set the vent position to defrost before starting this procedure. You will see why later.

The data lines show an actual mode door position and a commanded mode door position. They do not even come close to matching.

I laid a fender cover on the dirty floor and set the parking brake pedal. The pedal hits me in the shoulder and prevents me from being able to maneuver around.

Now I am ready to get in there and work.

I start by removing the push pin that holds the driver’s floor vent extension in place.

With the push pin released the duct extensions pulls easily from the stationary duct.

The lower screw for the actuator is just above the duct work and cannot be seen. It has to be felt. 5.5 mm head

The second screw can be easily seen as it is at the upper edge of the actuator. Note that it also holds the wiring harness in place.

I have developed a slightly different twist to this repair procedure. I could not take good enough pictures  from under the dash so hopefully I can show you how on the bench and you can transfer that knowledge to the vehicle.

With the two mounting screws removed and the wiring disconnected, use your fingers and thumb as leverage to push the cam/cog from the actuator shaft. The goal is to leave the cam/cog in place on the end of the heater-a/c case and to remove the actuator motor only.

The old assembly on the left and the new one on the right.

The old assembly separated

Taking the new actuator motor and installing it on the old cam/cog. Remember these steps will be done under the dash. Except for removing the new actuator motor from the new cam/cog, that can be done anywhere. I am just doing this on a bench to give you a clearer idea of what has to be done.

The old cam/cog with the new actuator motor installed.  Note the positions of the cam/cog in relation to the motor. Assuming that your actuator has failed in the most common position, blowing out of the defroster vents only, you should not have to do anything other than installing the actuator motor. No indexing of the door shafts to the cam/cog or recalibration of the actuator motors. This is a big time saver.

If you need to purchase one of these actuators please click here.

I recently had to go behind someone that could not properly install the actuator. The actuator and cog were removed from the truck. I installed the cog with the upper peg inserted into the outer slot. I then moved the cog around so that the center/rotating boss dropped into it’s mating position on the HVAC box. Installed the actuator onto the cog and bolted it down. Once connected and activated the actuator turned the cog counter clockwise and indexed the gear tooth lever perfectly. I was a little surprised by this so I tried it several times and every time it aligned properly. When looking at the white geared lever there is one long tooth and when rotated that long tooth should overhang the last black tooth on the cog.  Do Not forget that the actuator needs to be recalibrated in order to work correctly.

2003 Ford Expedition, Clicking From Rear A/C Actuator

This 2003 Ford Expedition came in  because of an annoying clicking sound from the back of the vehicle. The customer stated that if he would constantly adjust the rear temperature setting the noise would go away for a little while. He was planning on taking a thousand mile trip soon and did not think he could stand driving that far with the clicking sound driving him and his family crazy.

Well in telling me his problem, he actually to me what was wrong. There are damaged teeth in the rear blend door actuator. I have dealt with this issue before.

Multiple panels have to be removed to reach the rear blend door actuator. Start with the rear overhead panel. It just pulls straight down. Make sure your hands are clean. The interiors are generally light in color and you will notice smudges as soon as you look through the rear view mirror.

Next lift the rear floor trim panel as shown below.

Remove the right rear seat belt bolt for the third row seating.

Remove the right rear seat belt bolt.

Remove the trim plug from the panel.

Remove the hidden screw.

Start unsnapping the upper right rear trim panel.

< There are clips at the front and the back.

Fold down the rear seat and remove the seat belt anchor bolt.

Loosen the weather stripping at the rear edge of the right rear door.

Unsnap the lower trim panel clips.

Remove the right rear sill plate from the floor.

I removed the cup holder/storage tray to gain access to the actuator and to be able to show you better images. I regretted doing this as I had quite a hard time getting the panel completely seated when I re installed it.

The blend door actuator. The actuator directly in front of it is the rear mode actuator.

The panel I mentioned removing earlier. Repair manuals do tell you to remove this panel to change the mode actuator.

Since I had removed that panel anyways, I removed a couple of the screws through that opening.

I also had to use a long reach to remove the other screws after pulling the panel away from the side of the vehicle. Just far enough to work. There are four screws in all and they all have 8 mm or 5/16″ hex heads.

The actuator once it is removed from the vehicle. Notice the drive shaft is “D” shaped. There are two versions available for this application “D”  and “Cross” shaped. I would recommend removing the old actuator  before ordering your replacement actuator.

The front side with the original part label.  Part number YL5H-19E616-AC.

I wanted to show you what the actual failure was so I released the clips around the outer edge of the actuator.

The actuator split in half.

It is a little hard to see but if you click on the next picture to enlarge it you should be able to see the broken/ missing gear tooth that I am pointing to.

2001 VW Beetle, Changing The Low Beam Headlight Bulb

This 2001 VW Beetle came in with the complaint that the driver’s side low beam bulb was not working. This is supposed to be a fairly simple job, but most that I have done have been a pain in the rear end. Literally wound up on my posterior once the assembly finally came loose. Hate it when that happens.

When you open the hood and look towards the back of the headlight assembly, there will be a slide bar. Look for the cross hatched plastic push button and depress it with a screw driver.

Then slide the handle up until it reaches the end of the slot. You may need to work it back and forth to clear the dirt out of the mechanism.

With the slide bar all of the way up, the headlight assembly should be pushed slightly out of the fender. Grasp the assembly around the edges with you fingers and pull and wiggle til it comes loose. Sometimes it takes several attempts. You may have to push it back in and pull it back out several times before enough debris is worked out so that the headlight will fully release. Once it is all of the way out, depress the thumb latch and remove the harness connector.

The blown bulb.

The new bulb lined up and resting in position. The spring wire latch hinges down to hold the bulb in place.

The spring wire latch in place. Well almost, If you click on the picture to enlarge it you will see that the wire is not fully installed into the hook.  I did finish hooking it. just did not take another picture.

On this type of wiring connector, I prefer to tighten it slightly to ensure a good connection. I did the same thing to the ground wire terminal as well.

The long bar on the headlight assembly is one of three alignment ribs. Make sure they are clean and apply a slight bit of water resist grease to the edges.

Take an air gun and blow out any debris from the inner housing. Also remember to work the locking mechanism back and forth to clear any dirt that may be in between the pieces.

A little more grease in the locking slides.

Push the light in and pull the slide bar back down, to lock the assembly into position. Imagine that the light even works. It looks a little orange due to the angle and the amount of daylight when I took the picture.

2000 Oldsmobile Intrigue, Drivers Air Not As Cold As Passenger Side Air

This 2000 Oldsmobile Intrigue has warm air blowing from the driver’s side vents and cool air blowing. Notice I did not use the words hot or cold when describing this problem. That would have made for a different cause and repair.

The driver’s side temperature reading after  about five minutes with the a/c on and a fully warmed engine. Notice that the temp is warm in a/c vent terms but definitely not hot. Hot in a/c terms would have to be in excess of the ambient temperature. Which today would have been over 100 F.

The passenger side temperature reading under the same conditions. Again this is cool but not cold in relation to a/c vent temps. Cold is in the mid 40’s

The diagnosis is low refrigerant charge. The proof follows. The refrigerant level in my recovery machine before I connected it to the car.

The refrigerant level after recovering all of the refrigerant from the system. Simple math 5.3 lbs minus 4.4 lbs. equals .9 lbs.

Checking the a/c label on the driver’s side strut tower tell us that this system is supposed to hold 1.88 lbs. So this car had slightly less than half of its needed refrigerant charge.

The vent temperatures after a full system charge is installed. Again a warmed up engine and the system has been on for about 3-5 minutes, with the doors closed and the system set to recirculate.

Notice that the driver’s side of the vent is slightly warmer than the passenger side is. That is completely normal and is is due to the fact that the evaporator core is closer to the passenger side vents. There is normally a 3-5 degree F difference between the far right and the far left vents on USA market car.

2000 Oldsmobile Intrigue, Driver’s Vent Blows Hot Air

This 2000 Oldsmobile Intrigue came in with hot air blowing from the driver’s side vents with the a/c on. Using scan data on my Tech 2, I had determined that there were issues with the blend door actuators on this Olds.  I had already removed the lower dash panels on the driver’s side to replace the ignition switch for another a/c problem on this car. Please click here to see that post. The driver’s side blend door actuator, also referred to as the temperature door actuator is in the center of the picture below. It is partially hidden from view by the curved black tube that is connected to the interior temperature sensor.

The actuator is held in place by two 5.5 mm headed screws and has one harness connector. I used a long 1/4″ extension, a  1/4″universal and a 5.5 mm socket to remove the two screws.

With the screws removed and the harness disconnected, the actuator comes out from the bottom.

The new actuator is in place and I am installing one of the screws in the picture below. Notice that my extension is actually going through the plastic bracket.

The new and old actuators side by side, and of course I prefer a genuine ACDelco part.  To order this part from my trusted supplier, please click here.

I also had to replace the passenger side blend door actuator on this car even though there was no complaint from the driver.  Notice the data for the RH Air Mix Position Feedback and RH Air Mix Position Requested. What I had noticed was that the Requested data line would change with input from the control head assembly but the Feedback would not. the reason why was because some one had disconnected the wiring from the actuator.

To replace the actuator the glove box door has to be dropped down fully. This starts with removing the phillips headed screw that holds the recoil cable to the door.

Drop the glove box open some more and then rotate the stop pegs. Once the pegs have been loosened they will pull out of the glove box body.

When I had fully dropped the glove box the first thing I saw was that the actuator was unplugged. I plugged it up and it went to full hot. Not good since it is July in South Carolina.

I used the same tools to remove this actuator but it sure was a lot easier.

Once the screws were removed it pulls straight off of the heater-a/c case.

Notice the white shaft in the center of the picture. That is the shaft of the passenger side temperature door that mates to the actuator.

Now all of that data is good and this one is almost done. There is still one more problem with this car but I will leave that for another post.