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.
The black/orange wire should have 12 volts – (negative) . There are two sides to every dc circuit. Positive and negative. Both must be present for anything to work. Place one lead of your voltmeter on the blk/orange wire terminal and the other on the blue wire terminal. With the key on you should have nominal battery voltage. Next connect your voltmeter leads between the two wires going to the blower motor and see what voltage you have. with the key on and the blower set to high you should have close to battery voltage. If you do not go back and recheck the voltages on the blue/light blue wire.
Sparky, Thanks for the reply, I bought a new module from the dealer and it still does not work. With the motor disconnected, I get 12V on one pin and 0V on the other of the 2 pin connector. I was re-reading the posts and noticed that the blk/org wire of the 3-wire connector should have 12V and mine does not. It didn’t before and still does not, is this an issue? If so, does ths blk/org wire head over to the fuse box? Also, I connected my daughter barbie jeep battery to the motor last night and the motor starts right up. Any more suggestions?? Thanks for your time.
Hi Spinkid,
Your module is faulty and is not sending a ground signal out to the other side of the blower motor. If you were to disconnect the blower motor you should find no power or very little power on one of the two wires that go to the blower motor.
You back probe the terminal as I show in one of the pictures. The metal bracket in front of the module makes a good ground test point.
I’m sure this will sound silly, but You list the voltage norms that you should get, but how specifically are you testing the wires when you test the blower power motor (i.e. where do you attach the black lead on the voltage meter and the red lead on the meter?)I’m very new at this, but have found the module easy enough, just not sure how to check the wires without causing some other problem.