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.
Hi Sparky, I appreciate this advice. I did everything you suggested and the only wire that didn’t operate as you stated it should, was the orange/black wire. I couldn’t get it to register anything + or -, on the voltmeter. I checked the front blower fuse and there was no issue. Not sure how to check the ground, as you stated. My blower is at a constant speed, about medium level and will not change. When you turn the power off, the recirculate fan goes on high. I’m at a loss. Any suggestions? thanks, Rob
The word “Auto” will be somewhere on the control panel if it is an automatic system. If not it is a manual system. Interestingly enough the blower motor resistor mounts in the same place as the blower speed controller on the auto system.
i’m not sure if i have automatic temperature or manual temp. control on my 2003 town and country, how can i check? I imagine that on automatic models, i can set a desired temp and the unit will cycle on and off trying to maintain this setting. I don’t have such system.
-12 volts and ground on your vehicle are the same thing. The point that I was trying to stress was that this wire needs to be checked for an actual ground circuit and not just for the absence of a +12 volt reading.
In your posts on “2003 Chrysler Town and Country Van Blower Speed Constant” you state that the 3 wire harness on the Blower Power Module should have -12 volts on the black orange wire. Is this correct or should this be a ground wire? I have Zero Volts on this when disconnected and the ignition is on. I have the +12 on the dk blue and the 2-10 volts on the center light blue wires.