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.
Ok Sparky i have a 2003 grand caravan. About 6 months ago my air blower decided to only work on high and low it stay low on 1-4 and then on 5 goes to high on every setting. the rear blowers change just fine. how would i go about fixing this?
Your problem is likely to be a poor/burnt connection at the blower speed controller or worn out brushes in the blower motor. A visual inspection followed by a firm bump of the blower motor when the inoperative condition is present should provide the answer.
I have a 2003 and mine blows sometimes and sometimes it don’t. It will delay before coming on and when you hit a bump in the road it will sometimes kick on.
It sounds like there may be debris in the fan impeller blade causing the vibration on high speed. The low or no speed issue could be many things and I would start by checking the connections and circuits at the blower resistor.
Howdy Sparky! I have a 2005 Town and Country with manual A/C. The blower motor slows down when I accelerate and vibrates when I set the blower to high. This is most notable when I turn left. Today, it did not turn on when I first started the car (the rear blower worked fine). Any idea what is causing the problem?