1998 Toyota Avalon A/C Inop

The blower, most of the push buttons and the outside temperature display were inop. Checked basic fuses and all were okay. I did some research and found that there is a problem with the outside air / recirculation motors failing and shutting down the control assembly. The motor is located behind the glove box. Before attempting this repair follow the manufacturers procedures for disabling the airbags along with all other safety instructions.

After removing the glove box assembly I started looking for the motor and connector. The connector is the white connector in the following picture that is above and slightly to the right of the Toyota label on the blower case assembly.

Avalon 31

I unplugged the connector and all functions returned except for the obvious fresh air / recirculation motor was inop.

Time to pull the blower case with fresh air / recirculate motor assembly. First the computer assemblies to the right of the case assembly have to be removed. There are screws / nuts located at the top and bottom that need to be removed.

I could not get good pictures of the upper bolts and nuts but the lower ones are visible in the lower right corner of the picture above and are clearly visible in the next picture.

After removing the computers I next removed the piece of duct work shown in the following two pictures.

Avalon 26

Next I removed the screw that was just below the previously mentioned duct work.

The next nut is located at the bottom of the blower case on the firewall behind the carpet. It really did not look like a nut but an 8mm socket fit and removed it with no problem.

The next screw is located directly above the insulated refrigeration lines shown in the next picture.

The last screws are the two phillips headed screws that hold the harness assembly to the blower case. They are located below and on either side of the Toyota label. The right one is partially covered by the yellow jacketed wiring harness.

Now you have to very carefully pull the blower case loose and roll it out from under the dash. Part attention to the positioning as you remove it as you have to duplicate it exactly in reverse to reinstall.
With the blower case removed it was very obvious that the link arm was damaged as seen in the following three pictures.

After removing the motor from the assembly a bulge was found in the plastic housing.

A new motor and link arm were installed on the case assembly and the assembly was reinstalled in the vehicle. There are some that recommend that the amplifier assembly also be replaced. However it has a dealer cost of over $400 and the customer did not want to invest that much money into the car. From my own personal viewpoint, it took ten years for the link arm to fail and allow the motor to move past its design parameter causing the lock up and chances are that it will take about that long to repeat the failure. Customer wants to trade the car after the first of the year.

1991 Lexus LS400 – Cranks & Stalls

Vehicle cranks normally but within a few seconds the engine starts to stall. If the throttle is pressed the engine will run but it surges severely. With a little research I found that the fuel pump on this vehicle operates at two different speeds and that the speeds are controlled by changing the supply voltage. 12 Volts during cranking and heavier engine loads and about 6-8 volts all other times. The pump would work normally on 12 volts but would not operate on the lower voltage. The easy test was to apply 12 volts positive to the black w/red wire located in the trunk behind gas tank trim cover. With 12 volts applied the engine cranked and ran fine. Diagnosis of faulty fuel pump. The black w/red wire is located in the upper plug and you can see the red stripe at the far right of the picture below.

The fuel pump is located behind the rear seat. The lower seat cushion has two clips that have to be depressed and the the cushion can be lifted and removed. The inner seat belt buckles have to be removed in order to gain access to two of the four bolts that hold the seat back in place. With the bolts removed the seat back has to be lifted straight up and off of the upper hooks.

Once the seat is removed there is a metal plate that is held on by adhesive. Slide a flat tool under the edge and slowly lift so the plate is not overly bent. Once that plate is removed you will see the actual pump cover as shown below. Before removing the actual fuel pump plate and fuel pump be sure to check the amount of gas in the tank. Anything over about half a tank will result in gasoline running out into the passenger compartment when the bolted on cover is removed. Also ensure there is adequate ventilation and no chance of sparks or open flames. Fuel can be very dangerous and caution should be observed. Follow the manufacturers instruction for replacing the pump. The fuel filter is located under the rear of the car above a metal shield on the driver’s side next to the muffler. I would of had more pictures of the disassembly however the floor under the rear seat was filthy and disgusting and I did not want to stay any longer than necessary. I had to do a lot of clean up just to feel comfortable back there.

1999 Mercedes SLK230 Blower Inop

Vehicle came in with complaint of no blower operation. Removed hush panel on passenger side below the glove box.

Located harness connector for blower motor power regulator.

Disconnected harness connector.

Checked for battery positive on the Red wire, battery negative on the Brown wire and variable positive voltage on the White wire as controlled by the fan speed switch.

Voltage on the White wire should be as follows:

Blower Switch Position
1 1.1 – 1.8 volts
2 2.0 – 2.6 volts
3 2.8 – 3.3 volts
4 3.6 – 4.3 volts
5 5.0 – 6.0 volts

All voltage tests were good with the exception of the White wire. The voltage was 5.8 volts on off, 1 and 2 speed positions. Voltage went to .8 volts at position 3 and zero at all other positions. I know I have a switch problem now but that does not explain the inop blower. More testing is needed.

Removed cover from rear of harness connector to enable terminal removal.

Reconnected the Red and the Brown wires to the blower power regulator in their original positions and left the White wire safely disconnected.

I then hooked up a sensor simulator and added 2.5 volts to the center terminal being very careful not to short any terminals together.

Still no blower operation. Checked power supply at the Red wire attached to the blower motor, power was present. Checked ground supply at Blue wire attached to blower motor, ground present. Diagnosis of faulty blower motor and Faulty blower speed switch.

The above two pictures show the melted brush holder and brushes in the blower motor.

Now what happened to cause this motor to burn out, well lack of maintenance. You see the cabin air filter had been severely neglected until the blower motor started giving troubles. It had been packed with leaves and dirt and had severely restricted air flow which over worked the blower motor. The blower motor cost $400+. The switch was damaged by a frustrated driver that had started aggressively using / abusing the switch. The switch costs $1100+ and was not replaced at this time. When the vehicle returns I plan on attempting to repair the switch assembly which is part of the a/c control head. Lessons learned!!!!!!!!!!!!!!!!

1985 Cadillac Fleetwood Brougham Low Fuel Pressure

This was not a particularly difficult problem but I thought it was interesting. Engine would die out on acceleration and felt like it was running out of fuel. Customer said it happened all of a sudden. Checked fuel pressure at service port located at rear of throttle body. Fuel pressure was at 5 – 6 psi. Much too low 9-13 psi is the correct range with 12-13 psi desired. I disconnected the fuel lines at rear of car and hooked up my injector cleaning machine with internal fuel pump so that I could check the fuel pressure regulator for proper operation. 13 psi, great, diagnosis of faulty fuel pump.

I drained and removed the fuel tank and subsequently the pump and sending unit and this is where it got a little bit interesting. The fuel pump was not completely connected to the sending unit by the rubber hose and there were no clamps present.

It amazed me that the car had been driven 156,000 miles over 23 years and this hose had never come off before. I asked the owner if she had hit a pot hole some time just before the car started acting up and she confirmed that the road she now drives on has many pot holes and she has been hitting them quite a bit recently.

2001 Ford Windstar Odometer, Cruise Control and Rear Blower Inop

Vehicle came in with customer complaint of rear a/c inop and the odometer / message center only has dashes displayed. This vehicle was a 2001 Ford Windstar but this repair applies to several years of Windstars.

Having seen this problem before I checked to see if any fuses were blown and fuse number 10 was blown it is the lighter colored blue in the picture. According to Mitchell On Demand, number 10 fuse supplies power to the following systems: Shift lock actuator, instrument cluster, climate control switch assembly, blend door actuator, power sliding doors, reverse parking aid, speed control, a/c clutch cycling pressure switch,rear defrost relay, and brake pressure switch.

Also as mentioned earlier I have seen this problem before and went to the culprit. The brake pressure switch on the end of the master cylinder. I disconnected the connector and positioned it out of the way and then replaced the fuse. All systems went back to work with the exception of the cruise control and it was not working because of the switch I had disconnected. I then referred the customer to the dealership as this part is under recall for catching on fire.

The brake pressure switch is located and the end of and on the bottom side of the master cylinder. The picture was taken looking down between the master cylinder and the breather tube. Disconnecting this switch will remove the short until the switch can be replaced and on most Ford vehicles it will be done under a recall. Contact your local dealer with your VIN number to see if the recall applies to your vehicle. If you need to change the switch yourself, have the new one ready, remove the breather assembly, unscrew the switch and screw the new one end, install wiring adapters that come in the kit from Ford and you are done.

1993 Buick Roadmaster Power Trunk Release Inop

Car came in with complaint of power trunk release inop. Would not work with remote or switch on dash. The first thing checked was that the valet switch in the glove box was not switch on. It was not. Checked for power and ground at trunk release solenoid located at the latch assembly. No power or ground. Traced wires around to the driver’s side hinge and found the wires broken about two inches from the connector.

Disconnected harness and brought it to the outside of the trunk where repairs could be made easily. Made up three new wires with factory type terminal and spliced them back into the harness while staggering the joints. Retaped and secured the harness back to the hinge and another vehicle repaired.

If you do not have ready access to factory terminals then you can splice the wires back together, however make sure you add enough wire to the harness to keep the wires from flexing at the splice connection when the trunk is opened or closed. This will insure a lasting repair.

1999 Taurus Cranks & Stalls When Put In Gear, No Run Condition

The engine cranks over normally and either stalls when put into any gear or fails to run at all. Checked codes and found no communication with engine computer. I also noted that during the stall condition or the no run condition that the service engine soon and door ajar indicator lights on the left side of the instrument cluster would not come on. The lights on the right side seemed to work okay. Unfortunately the problem went away and started running fine during inspection.

I consulted wiring diagrams to find a common link between the the two inoperative lights and possibly the no run condition. The only commonality that I could find was a fuse that is powered by the ignition switch. An ignition switch could cause a no run condition so that is where I started. I removed the panel below the steering column and I was pretty sure I had found the problem. There was an add on security system!! Lots of troubles.

I disconnected the large plug and tried to start the vehicle and the problem returned exactly as it was before. I consulted the owner and asked if she was using a remote control to lock and unlock her car. She said no and removal was recommended. Restored wiring to factory design and all is good.

2005 Chevrolet Silverado Blower Inop

This is a very common problem on 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 and 2007 Chevrolet Silverado and GMC Sierra trucks. Over a period of time the resistor and usually the connector overheat and blower operation stops in some or all speeds.

The blower resistor is located on the passenger side of the vehicle behind the glove box. There is a plastic cover that has to be removed to gain access to the resistor and wiring.

After the cover is removed disconnect the harness connector and inspect for damage. On this particular vehicle the only terminals that were damaged were the third from the right and the third from the left. Sometimes all of the terminals will be damaged and the plug will be melted to the resistor as shown in the last pictures.

After thoroughly inspecting the connector for damage the terminal retaining comb was removed from the old and the new harness connectors. The good wiring was transferred one at a time from the old connector to the new connector. A terminal extracting tool is needed to do this. The locking tab must be slightly depressed before the terminal can be removed from the connector. A solid piece of wire such as a larger paperclip could be used if a tool is not available. If you do not have an adequate tool or experience this should not be done. Cut the wires one at a time and splice in to the harness using a quality butt connector.

Be sure to stagger the spliced connectors as much as possible in order to have a neater and less troublesome repair.

Retape the harness and install the new blower resistor and harness connector. As with any wiring repair that involves a burnt connector, the connector and the component that it attaches to must be replaced at the same time or the repair will fail very quickly.

This connector like many that will be found was melted to the resistor and every wire had to be replaced. You can save yourself time and money by always being aware of changes in your vehicle and repairing them as soon as possible. If you need quality parts click here.

I recently completed a video on this repair as well. Please click here to view.

I am adding testing instructions due to popular demand. Testing is as follows. Disconnect the 7 wire harness connector and inspect. If there is any sign of heat damage replace both parts per above instructions. If there is no sign of heat damage then check the following. With the 7 wire harness disconnected check for power on the red wire. It should have 12 volts at all times and it gets it’s power from the 40 amp blower fuse in the under hood fuse box. Next with the key on check for 12 volt power to each of the following wires as you move the blower speed switch from low to high. Yellow / low, tan / med 1, lt blue / med 2, purple / med 3 and orange / high. Remember, this test is done with the key on and the seven wire harness disconnected. Other than the red wire having power at all times, only one wire at a time will have power on it, during a proper test. If there is no power to any of these wires during the test , check the fuse in the driver’s interior fuse box. If only some of these signals are missing, you will need to inspect the blower speed switch and related wiring. Also you should do a drag test on the terminals to check the spring tension. Please click here for more instructions

  • Terminal “A” Tan = Speed 2, power through blower switch from HVAC fuse
  • Terminal “B” Yellow = Speed 1, power through blower switch from HVAC fuse
  • Terminal “C” Purple = Speed 4, power through blower switch from HVAC fuse
  • Terminal “D” Lt Blue = Speed 3, power through blower switch from HVAC fuse
  • Terminal “E” Black = Blower system, ground at all times
  • Terminal “F” Orange = Speed 5, power through blower switch from HVAC fuse
  • Terminal “G” Red = Speed 5, Constant power from BLWR fuse under hood

If for some reason the blower does not work at all and there is no power on any of the wires except the red , you may want to see the recent information I published about a new problem that has occurred. Please click here to see that article.

If all of the tests above are okay and you want to go a step further, place a test light or voltmeter in the wires going to the blower motor. If the light comes on or you have a 12 volt reading, the resistor and wiring are okay and the blower motor is faulty. This can also sometimes be confirmed by bumping the blower motor with the switches on. If the motor starts after bumping the motor is faulty. One can also remove the blower motor and apply 12 volts (power and ground) directly to the motor. Be careful though the motor will tend to jump and roll all over the place. Hold it firmly and be sure you are clear of the impeller as it could hurt you pretty easily.

One other note. If you have an amperage gauge, test the blower amperage draw while it is mounted in the blower case. Turn on surge amperage could go up to about 28 amps. Amperage draw at high blower should be in the 18 to 24 amp range. The lower the better. Restricted cabin air filters (if present) and dirty evaporator cores will cause a blower motor to draw more current while reducing air flow volume. These two conditions combined will significantly reduce the life of any blower resistor.

More additions to make parts identification hopefully easier. The following picture is of a floor mounted center console. In ordering, this is one of the most important features that we need to know about your truck. Please be sure to leave this information along with year, make, model, engine size, type of cab (regular, extended or four door) and confirmation that you have manual a/c. Leave this info in the customer comments box at check out when ordering. You may also email us anytime or call us 8:00 am to 6:00pm EST

The following picture is of an original two piece blower resistor that has been updated to a new design which is a single piece unit. If your truck has the two piece resistor, both pieces must be removed before replacing with the new single piece resistor.

If you have any questions related to this post please email me at info@the-electric-connection.com I just finished a video on this as well. Please click here to view.

2001 Chevrolet Blazer,4WD, Rough Run, Code P0122, Transmission Replaced Last Year

This vehicle was brought in after being at another shop as usual. Code P0122 was stored for low TPS voltage. Checked the TPS and connector and all was okay. Strangely enough I did some online research and found a post of a similar problem and it related to a 4wd vehicle that had also had the transmission repaired several months earlier. I put the vehicle on the lift to see if it was this Blazer’s problem. Sure enough there was a shiny ring on the front drive shaft and just above it was a misrouted wiring harness.

I unhooked the harness connector above the transmission, repaired the damage and rerouted the harness to the factory retainers that were still in place on the crossmember.

1993 Acura Legend, No Run Condition

Car came in with a very classic complaint of the engine will not start sometimes and customer has noticed a change in temperature seems to make a difference. This is a very common problem with both Acura and Honda. What happens is that the solder joints on the main relay circuit board will weaken over time and eventually go open. First start by removing lower dash cover to expose the relay.

Main Relay 1993 Acura Legend

Next remove the relay and using a small screwdriver or other flat prying device remove the circuit board from the case assembly. Using a magnifying glass inspect the circuit board for open terminals. These will be indicated by a black ring in the solder joint usually at the outer edge.

You can now choose to replace the relay assembly or resolder the joints as needed. All of the joints need to be checked but especially the ones that relate to the two relays that are mounted to the circuit board.

There have also been a few cases of the ground wire under the right injector cover being left loose and causing a similar complaint. It only takes a couple of minutes to check.