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.
Either the two wire connector also has a problem or the brushes in the blower motor are nearly worn out. Next time it stops just bump the motor housing area and see if it jumps back on.
Thanks for posting this info.
I’ve replaced the blower speed control twice in the past four years on my 01 T&C LXi with auto heat/AC controls. Eventually the three wire connector melted and severely damaged the wires. I spliced in new wires and have three spade connectors to keep straight rather than replace the whole harness. No more melting over past two years 🙂
I could swear I’ve heard squealing from the motor over the past couple months, and yesterday during extreme cold weather of zero degrees the front blower would not work. Same this morning for 3 degrees.
Put the multi-meter on the various wires and performed your tests. The three wire harness checks out fine, but the highest voltage I could read on the two wire was 10.9 volts. Does that indicate a short in the blower motor?
Oddly enough, while I was running the test on the two wire connector the blower motor randomly kicked in.
No, If you follow the two wires they will lead you to the blower motor. If you will test, you will determine if the blower motor is a problem or not. An inexpensive multimeter costs less than what you have already spent and currently you still have a broken system. I do not want to seem condescending but if you are not familiar with jumping power and ground to your blower motor then you are likely in over your head.
OK.. so if I trace that wire, I find my potential culprit.
And is it a really dumb question to ask how to jump the power? 🙂 (feeling like I’m getting in over my head, but I would love to fix this one on my own…!)
Thanks!
The two wire connector with the green and black wires lead to the blower motor. You can disconnect the harness connector, jump power and ground to the blower motor, to see if it is working or not. Diagrams can be purchased from Mitchell, AllData or Chrysler.