2003 Chrysler Town and Country Van came in with the complaint of the blower operates on high speed with key on and cannot be adjusted down. This procedure will also apply to Dodge Caravans with auto a/c. The controls and indicators seemed to work normally. I checked the wiring diagram and component locator and found that the blower power module is located behind the glove box. Good place to start.
After opening the glove box there are two stops the have to be depressed inward in order to drop the box down.
The blower power module is directly behind the lowered glove box. It is held in place by two 8mm hex head screws.
After removing the two attaching screws, the blower power module can be positioned for testing.
Turn the key on and while manually rotating the blower switch from low to high you should see a voltage change between about 2 volts (high)up to about 10 volts (low) on the blue/light blue wire. It is the middle wire in the left connector pictured below. Because the blower was working on high speed there was no need to do any other testing, however if you were to have low blower or no blower you would need to test further. Check for 12 volts – on the black/orange wire and 12 volts+ on the dark blue wire in the three wire connector. If either is missing check respective fuse and ground connections. Next check for 12 volts between the blue wire and the dark blue /yellow (sometimes black as pictured below) wire in the two wire connector to the right of the pictures. If either signal is missing in the two wire connector and the three wire connector tested good then the power module is faulty. If 12 volts power and ground are present then the blower motor is faulty. Usually bumping the motor with the key on and the blower switch on high will make the motor work for a little while because it will reset the worn brushes.
Three wire connector:
Black/Orange wire should have a constant ground.
Dark Blue wire should have 12 volt switched power from the front blower relay. The front blower relay is located in the Integrated Power Module (underhood fuse box).
Blue/Light Blue wire should have a varying voltage from about 2 volts(high blower command) and a nominal 10 volts(low blower command).
Two wire connector:
Check for a nominal battery voltage reading across the two wires. Key on and blower set to high.
I removed the mounting screws to gain better access to the wiring for testing.
Be careful to keep the aluminum cooling fins away from the metal brace for the glove box. It will complete the ground circuit for the blower motor and will scare you when it sparks.
Place an insulating cloth between the aluminum fins and the brace if you want.
A good look at the blower power module.
Installed the new blower power module and all is well.
Thanks for the info. I’ll post the solution when I find it.
I checked the diagnostic information in my Mitchell system before I left the shop today. Unfortunately it stated that a scan tool is needed to access the system. So you will have to have the codes read by someone with the proper scan tool or slowly deduce what might be wrong by observation.
That would be super. I really appreciate the help!
It would seem that you may have a control issue. I think there is a self diagnostic system built in to the control assembly. I just cannot remember what it is tonight. I will try to look it up for you but it may take a couple of days because I have a lot of work to do at my shop.
Sparky, Thanks for your reply! But I’ve checked the refrigerant level and topped it off…fully charged. It really seems like a controller issue. BTW, I have a 2001 T&C Limited with digital controls for all (driver/pass/rear). Sometimes while driving, set to low/low/low & recirc and it’s blowing warm/cool/cold, for no apparent reason it will just start blowing ICE cold air from all vents. I mean so cold it hurts if its blowing on ur face. Even if I turn off the recirc, it stays pretty cold. Then I park, shut off, start the next day and maybe it blows ice, maybe warm/cool/cold. Like you said, on a hot day the fresh air will be too warm and Auto mode will kick in the recirc mode. But even that doesn’t make it go from this funky “front warm–back cold” mode back to ice cold. Why would the rear always be cold? What component regulates the temperature for the front? Is there something mechanical I can check? Is there a seperate A/C controller for mixing hot and cold air for various temperature settings? Or is that part of the main engine computer?
Thanks a million!