Page 22 – Sparky's Answers

2004 Chevrolet Silverado, Changing The Mode Actuator

This 2004 Chevrolet Silverado came in with the complaint that the air only blows through the defrost and will not blow out of any other location. There were codes B0263 and B3770 stored in the HVAC module. The codes refer to mode actuator faults.

To access the actuator, the driver’s side heater floor vent extension has to be removed. There is a single push pin that holds it on.

With the push pin removed from the vehicle the vent extension can be dropped down and pulled off of the main heater- a/c case.

The actuator is located above the driver’s floor vent at the heater case. There are two 8 mm headed screws that hold the actuator to the main assembly. The 8 mm screws are used if the system has manual controls but has a factory floor mounted center console. If the system had automatic controls or there was not a factory installed floor mounted center console, the screw heads would be 5.5 mm. Also a different actuator part number would be used and the procedure would be slightly different.

The actuator cog gear as it should be installed in the vehicle without the actuator attached.

The old actuator. It has two different numbers printed on the label. 3B1H-19-E616-JA and 00003381A. Neither one of which is the actual replacement part number instead they are the manufacturer’s part number.

In the picture below you can barely see half of the 8 mm headed screw at the lower mounting hole. It is about 3/4″ below the lower right hand corner of the label in the picture below. The second mounting hole is about 1/2″ above the upper right hand corner of the label.

Just a picture to show you the general orientation of the actuator as it is installed under the dash. The picture was taken from the brake pedal area, looking up and towards the center of the dash.

The most needed tool for this job is an 8 mm universal socket. I also used various extensions, ratchets, pliers and a flash light.

I did need an 8 mm wrench to start the upper mounting screw. The full set of tools I used to change this actuator.

I mentioned this earlier but I just wanted to elaborate a little more. ACDelco is the parts supplier of this part to General Motors and ultimately you and me. Woory is the actual manufacturer that makes this part according to GM specifications.

I point all of this out because Woory does manufacture this part for the aftermarket as well. However it will be made to the aftermarket parts suppliers specifications and not to the specifications required by General Motors and ACDelco.

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

1993 Ford Escort, Transmission Will Not Shift With The Tail Lights On

This 1993 Ford Escort came in with the unusual complaint that the transmission would not shift with the tail/park lights on. From experience it seemed like it would be a faulty ground. I checked all of the grounds under the hood and all were okay. Since my faulty ground thoughts had not panned out I turned my attention to checking to see if all of the park/tail lights were functioning properly. The tag or license plate lights were not working. Opening the trunk found the answer. I do not think the Ford Motor Company intended the trunk wiring harness to be swinging around like this.

A closer inspection of the wiring found that there were broken ground wires behind the hinge area.

You may have to click on the pictures to enlarge them for a better view.

I stripped the harnesses open.

Then proceeded with splicing the wires back together. Note that I went beyond the actual break point in both directions so that the splice connections would not be subjected to movement. If a splice is made at a point of movement the wire will fracture on either side of the splice in a fairly short period of time.

I also had to repair the other wires even though initially they looked okay. A firm pull on the wires at the flex point revealed that the wires were broken inside the insulation. When pressure was a applied the plastic insulation stretched.

The wiring harness repaired and taped back up into a harness assembly.

I attached the wiring to the hinge with a wire tie and routed the harness to the it did not flex at a specific point. Instead it gently moved the whole harness.

I had installed the harness into all of it’s hold down points along the inside of the trunk lid.

It had been obvious to me that something was missing from the right side of the hinge and I found this laying in some junk inside the trunk. The clips were too broken to use it in this repair.

Now the reason for the customer’s complaint of the transmission not shifting when the park lights were turned on. With the grounds broken for the license plate lights there was power being back fed into the reverse light bulbs and then eventually back to the PCM. This false signal was sending the transmission control into limp mode.

The transmission was back to shifting properly with or without the park/tail lights on.

1997 Suzuki Sidekick, A/C Is Cool But Not Cold

This 1997 Suzuki Sidekick came in with the complaint that the a/c would come on and blow cool for a minute or two and then the air would turn warm. The customer had taken the vehicle to several shops before arriving at mine. It only took a minute or two to see the pressures climb on the low and high side of the system. My first thought was that the system was overcharged but then I noticed that the electric condenser fan was not coming on. A little bit of inspection and I found the cooling fan relay hanging next to the radiator on the driver’s side of the vehicle. This repair was going to need a new relay and harness connector.

It was pretty obvious to me that the damage was caused by water intrusion into the unsealed connection.

I decided to replace the relay and harness connector with sealed units. I stripped the harness back far enough to find good clean wiring and then went about installing the new sealed connector. This particular connector has a sealing panel on the rear of the connector. The wire has to be slid through the panel and the connector body. The terminal is then crimped on using a special set of crimping pliers.

The wire and terminal are then pulled back into the connector body where it latches into position.

I repeated the process on all four wires to complete the connector installation. Below is the side view of the finished connector repair.

The terminal end view of the completed connector.

In the pictures below you will see all of the components for this connector and others. The connector bodies with the red end are the reverse view of the connector body that I used. Also note that the green silicone gasket seals the seam where the connector body and the relay meet. All of these seals create a highly water resistant assembly.

2004 Volvo XC90 , Power Window Does Not Work

This 2004 Volvo XC90 T6 AWD came in with the complaint that the passenger front power window does not work. It is in the full up position and when the switch is tried in the up position it bumps up and flexes the door panel. Sometimes in the down position it will bump slightly but not actually move any distance. The customer informed me that the door had recently been repaired from an accident.

The first thing that I had to do was figure out how to remove the door panel, so that I could do some testing. The trim panel with a speaker that covers the mirror mount was easy to unsnap from the door.

I assumed that there would be a harness connector under the foam panel.

There it is. The locking tab has to be pushed in before the harness connector can be removed.

The connector slides out after the lock is depressed.

I used a plastic pry bar to lift each side of the door pull handle.

I just had to lift it slightly on both sides.

So that there would be enough room to slide it in at the horizontal parting line.

The cover will then lift out of the way.

I removed the two torx headed screws that hold the panel to the door.

I had tried earlier to pull the edges of the door panel loose and it would just barely budge. However after the two torx screws were removed the rest of the panel unsnapped quite easily. A firm pull all the way around the edges and the door panel fell off. I would recommend preparing yourself to catch it before it falls drastically and causes damage.

Tilt the top of the panel away from the door and release the door handle cable. There are two latched that have to be spread apart. Then lift and pivot the cable from the handle.

In the picture below you will see the passenger door module. It is a mini computer for controlling door functions.

I disconnected the harness shown below with the larger wires and grey connector. I had already looked and a wiring diagram and found that the large red wire is the main power input to the PDM. It has continuous battery voltage and is supplied through fuse number 6 in the driver’s door fuse box.

The large black wire has battery ground on it at all times. The medium sized Violet and Red/Black wires go to the power window motor. I used two fused jumper wires to perform the next step. One fused jumper was connected to the Red wire and the other to the Black wire.

Remember I used two fused jumper wires with a total of four leads to do this test. I connected the wires as listed below. The window went up and down when I commanded it to using the sequences below.

Up = Red Connected to Violet and Black connected to Red/Black

Down = Red connected to Red/Black and Black connected to Violet

Since the window motor actually worked in both directions I surmised that either the motor position sensor or the PDM were faulty. I had to do some research.

My research found that the system may just need to have the upper and lower limits relearned. Volvo refers to an initialization procedure. It is recommended to use the Volvo Factory scan tool to do this but I was able to come up with the following procedure. It involved locating the proper fuse in the driver’s interior fuse box. A small screwdriver or similar tool inserted into the slot will allow the panel to be removed.

As mentioned fuse number 6 powers the PDM and it is the one we will be working with. The legend on the inside of the panel confirms that fuse number 6 is indeed for the PDM.

It also shows us the location of fuse number 6 in relation to the fuse box.

I am grabbing fuse number six with my pliers. This is in preparation of the following procedure.

The window that is being initialized has to be partially down. After doing my testing that I outlined earlier I left the window halfway down.

All module and harnesses have to be fully connected.

Turn the ignition switch on.

Prepare to remove fuse number 6 for the passenger window. Fuse number 5 for the driver’s window.

At the driver’s master switch hold the front passenger switch in the up position.

Remove the fuse while the window is in motion.

Release the switch.

Install the fuse.

Finish raising the window from the same switch used earlier.

Hold the switch for five seconds after the window has reached the full up position.

The process is now complete.

Fuse number 6 for the PDM

Fuse number 5 for the DDM.

2004 Chevrolet Trailblazer, No Low Beam Headlights

This 2004 Chevrolet Trailblazer came in with the complaint that neither one of the low beam headlights would work. They both stopped working at the same time. The customer had already paid another shop to have the headlight and dimmer switches replaced. After several days of trying hit and miss diagnosis she called me. I told her that I should be able to have her vehicle in and out of the shop in less than fifteen minutes and the bill would be around $65.

The first step in this easy repair is to locate the underhood fuse box assembly, located under the hood on the driver’s side of the vehicle.

After removing the outer cover, you should find an inner cover that also will have to be removed.

On the inside of the main fuse box cover there should be a fuse box legend. On the far right hand side of the legend is a listing for solid state relays. The relay we are looking for is designated as an HDM relay. It is identified as being relay number 46.

Looking at the legend for part number 46, we find that it is located nearly in the center of the fuse box but slightly towards the fender.

Here is the actual relay in the fuse box. The first thing that I noticed was that the relay had a different physical appearance compared to a factory relay. It should have been black, shiny and had the part number stamped on top. The part number is 15016745. It should have looked just like the relay located next to it that is designated as relay number 45. This relay had already been replaced with an aftermarket relay once and it had failed again. I strongly recommend using the original equipment relay if possible. They just last longer. To purchase the relay, click here.

It takes a firm grip to grasp the relay and pull it from the fuse box. A pair of pliers can be used, just make sure you don’t grab it too tightly and crush it.

Now the simplest was to test the relay is that if you know relay 45 is good, remove it. Also note that there are numbers next to the terminals on the underside of the relay.

Terminal #1 is not used.
Terminal #2 should have battery power on it at all times.
Terminal #3 is not used.
Terminal #4 is the relay output terminal to the low beam headlight fuses #3 & #6.
Terminal #5 is switch battery power from the BCM. I do not recommend testing this terminal with a test light.

Terminal #6 is continuous battery ground and is terminated at the lower left side of the engine.

In doing testing, take your time and do not allow yourself to be fooled by mirror images. I always place my finger on the relay terminal that I want to test and then rotate the relay into position to identify the corresponding terminal in the fuse box.

Then install it into the relay 46 position. If the headlights work, you know that you will need to purchase a new relay. I know the temptation is there to just swap relays but keep in mind that relay 45 is for the engine fan clutch. You may wind up with an overheating condition if you do.

The new relay has been installed for the low beam headlights and the original relay for the fan was restored to it’s location. I personally recommend changing both relays while you are there but I will leave that up to you. If you would like a deal on buying both relays, click here.

The headlights now work again and all I have to do is install the rubber cover over the low beam opening in the rear of the headlight assembly. The last shop left it off and the customer asked if I would install it.

The last word on this repair is that if you remember the relay had already been replaced with an aftermarket relay once and it had failed again. I strongly recommend using the original equipment relay if possible.

2003 Nissan Maxima, Changing The Cabin Air Filter

This 2003 Nissan Maxima had a faulty blower resistor and as a result I wanted to look at the cabin air filter as a possible cause of the resistor failure. To see that repair please click here. The cabin air filter is located behind the glove box area and the glove box has to be removed. To do that the kick panel and rocker panel trim have to be removed. The plastic nut at the top of the kick panel will unscrew with just finger pressure.

The rocker trim panel has to be lifted at the rear edge and removed from its location.

With the rocker trim panel out of the way the passenger kick panel will now come out.

Removing the lower left glove box retaining screw.

Removing the lower right glove box retaining screw is the reason why the kick and rocker panels had to be removed.

There are a total of four screws that have to be removed along the upper edge of the glove box opening. Two in the center at the latch area and one in each corner.

Ease the glove box assembly down and detach the light assembly and the airbag connector from the glove box housing. there is no need to disconnect the airbag connector. If for some reason you decide to you must disable the airbag system according to the manufacturers instructions.

Finish removing the glove box assembly. The white vertical strip behind the glove box is where the cabin air filter is located.

There is a small spring clip located at the bottom of the filter cover. I used a small screwdriver inserted into the slot to flex and remove the clip.

Be careful not to lose this clip.

With the clip removed the white plastic strip will slide up. Then it can be pulled away from the box.

I slid the bottom filter out first and then the top.

There was good bit of debris that had gotten past the filters and I had to use a small hose attachment that I made for my shop vacuum to remove the debris.

Nice new filters being installed into the heater- a/c case.

The filters are marked with the word up and an arrow to indicate the desired installation direction.

2003 Nissan Maxima, No Low Blower Speeds

This 2003 Nissan Maxima came in with the complaint that only the highest blower speed was working. The air would not blow at all, on the lower speeds. Suspecting a faulty blower resistor, I went to the passenger side of the dash.

The blower resistor is located near the firewall under the passenger side of the dash. It is the piece that the connector with blue wires is attached to.

Two phillip’s headed screws hold the resistor to the blower housing.

In the next picture, you can see the burnt mark at the right hand side.

To release the locking tab, it needs to be pushed in where I am pointing at with my pocket screwdriver.

If you want to test the system this is what you will need to know.

The blower resistor and blower switch are on the ground side of the blower motor circuit.

With the resistor harness disconnected and the ignition on, there will be bleed through battery voltage on the larger blue/white wire. In the blower switch position 4 or high the blower switch directly connects this wire to chassis ground and the highest blower speed is achieved.

When the blower speed is set to the 3 position the ground is sent from the blower switch to the resistor on the blue/red wire. It passes through one resistor and the speed is reduced slightly.

When blower speed 2 is selected the ground again is sent form the blower switch to the resistor but this time it is sent on the blue/yellow wire. At the resistor is passes through two resistors and the speed is dropped even further.

When blower speed 1 is selected the ground signal again is sent from the blower switch to the blower resistor and this time it is on the blue/black wire. At the resistor is passes through three resistors and the lowest blower speed is achieved.

If there is no bleed through voltage at the blue/white wire you will need to see if there is power on the white/blue wire at the blower motor itself.

If voltage is not present on the white/blue wire at the blower motor you will need to check the fuses and relay. If power is present the blower motor is faulty.

I also wound up checking and changing a restricted cabin air filter in this vehicle. It is likely that the dirty filter contributed to the resistor failure. To see how to change the filter please click here.

1998 Jeep Grand Cherokee, Changing The Map Light Bulbs

This 1998 Jeep Grand Cherokee Limited came in with the complaint that the overhead reading or map light was not working on the left side. This repair starts with removing the single front phillip’s head screw.

It took me a little while to figure out how to unsnap the rear of the light assembly. I used the tools shown below to slide into where the clips were and pried it loose.

The retaining clip.

The slot that the retaining clip locks into.

This picture will give you a better idea of just where those clips are in relation the whole assembly.

I unplugged the red connector near the compass assembly and the harness connector for the sunroof switch. Then I removed the two T10 torx screws.

This of course allowed me to flip the lamp base over to expose the bulbs.

I was pretty sure that the lenses were not removable from the exterior of the assembly and the picture below proves that theory out.

I lifted one end of each bulb with a small screwdriver, and then pulled the other end loose.

In case you are interested, the bulb number for this vehicle is 212-2.

2005 Nissan Maxima, Park/Tail Lights Do Not Work, Fuse Blows

This 2005 Nissan Maxima came in with the complaint that the tail lights do not work and the fuse blows. The tail light fuse is located in the underhood fuse box on the passenger side of the vehicle. The black plastic trim panel that runs from the firewall to the headlight assembly has to be removed. There are several push pin retainers that hold it in place.

With the trim panel removed grab the fuse box cover and pull it up and off of the fuse box. Note the position of the tail light fuse on the fuse box legend. Be careful around the fuse box and use a gentle hand. There is a processor built into the intelligent fuse box assembly.

Locate the fuse in the fuse box and test both sides of the fuse. This one had power on one leg but not on the other. I replaced the fuse and the park/tail lights started working again. Normal inspections of the bulbs and related wiring found nothing. I started bouncing the body around to see if the fuse would blow. Nothing. I started opening and closing the doors firmly and the fuse blew. Replaced the fuse again and the lights stayed on.

While sitting in the car contemplating what to check next, I noticed that the dome light switch in the overhead console was not sitting properly. A gentle wiggle and the fuse blew. I knew this because the dash illumination lights changed in intensity. A little more wiggling and the switch fell apart.

I made sure all of the pieces were out and replaced the fuse again. The lights worked and no matter how many times I moved the car around or opened and closed the doors the fuse remained good.

I found it strange that there would be a tail light circuit attached to the dome light switch and I could find no reference to this in the wiring diagrams.

Although I was sure the problem had been located, I now had a switch that needed to be replaced. There is one screw (phillips) that holds the assembly in place along with several clips.

It takes a good bit of force to dislodge the retaining clips. I used a wide plastic pry bar aimed at the white plastic clips to dislodge the fasteners.

Once the leading edge fasteners were free the two metal clips at the rear of the assembly were easy to remove.

The dome light switch unplugs from the back of the assembly. The switch and harness are then removed from the front of the light assembly. I called my Nissan dealership to find out that the switch is not sold separately. The cost of the assembly is $350 and only four in the country.

I did some testing and found that if I connected the white wire to the orange wire the dome light would work as if the switch was placed to the auto/door position.

A couple of snips. A splicing connector, some heat shrink tubing and the dome light works as most people expect anyway. Open the door and it comes on. Close the door and it turns off. Slight delay since it is a Nissan design. They prefer their dome lights to fade out gradually.

So if you have a hard to find short in the tail light circuit be sure to check this switch out. If you also do not want to spend $350 on a new light assembly but want the dome light to work, just connect the orange and white wires together as I did. I would strongly recommend checking the wire locations and electrical circuits yourself. Sometimes manufacturers will change the wire color codes for internal wiring and yours may or may not match this one.

The park lights now work without the fuse blowing and the dome light works as the customer requested.

2000 Ford F350, A/C Not Cold Sometimes

This 2000 Ford F350 with the 7.3 liter diesel engine came in with the complaint that the a/c works sometimes. It seemed to work okay when a cold engine was started but as the engine warmed up the a/c would stop cooling.

This one was easy enough to diagnose just by looking at the air gap at the compressor clutch hub. Normally the gap should be in the .015″ to .025″. This one had a gap of about .050″. A test that can be done is to run the engine with the a/c on and the blower set to the lowest position. Windows up and doors closed. Keep the engine speed between 1500 and 2000 rpms for a few minutes. Then let the engine idle for an extended period of time until the a/c starts cycling off and then back on. Check in on the operation until the a/c fails to cycle back on. Using a wooden broom handle or similar device, tap the clutch hub to see if it will engage. If it does you have just proven that the air gap is the problem. Be careful when doing this so that you do not cause harm to yourself, others or your vehicle. If you have any doubts about it do not do it!

In order to correct the air gap, the clutch hub will need to be held with a tool similar to the one in the next picture.

Then using a small ratchet and socket loosen the 8 mm headed bolt.

Finish removing the bolt from the compressor.

Then realize that you should have already removed the coolant tank to make life easier. It does have to be moved to slide the clutch hub off. There are two bolts that hold it in place.

A little gentle wiggling and the clutch hub should slide off of the shaft. Be on the look out for the shim. It may stick to the shaft, stick in the hub or just fall off.

This one had stuck in the tube in the clutch hub. A small screw driver was used to pull it out. Since the shim was about the thickness of the excessive gap, I did not install another shim.

I installed the clutch hub, without a shim, and checked the clearances and it was within an acceptable range. I installed the retaining bolt and mounted the coolant reservoir tank back into position.

Another one fixed. Obviously the better fix would have been to install a new clutch assembly and or a new compressor assembly.