Chrysler Repair: Fan runs on high only and all the time, eagle vision tsi, automatic climate control

Question
Roland,
I have a 1997 Eagle Vision TSI with a blower motor problem.
The problem is that the motor runs only on high and will not turn down or off
Even when the automatic climate control center is off the fan still runs on high and squeals and wines

Please help any information will be greatly appreciated
Could it be the Climate control resistor block?
And if so were is this resistor block located?
Please help winter is fast approaching an I live in Vermont


Answer
Just to follow up, though I don't have the wiring diagrams for the car, in the models thru '92 there was a fuse that fed 12V to the blower motor on a dark green wire and then the return wire from the blower would have various amounts of resistance placed between it and ground to change the voltage that actually powered the motor. One possibility is that the black/tan wire between the motor connector and the power module is grounded, which results in the fan having the full 12V across it and it would run at full speed and also of course run all the time. So check to see if that black/tan wire might be grounded. You could for example unplug the balck/tan wire at the end that goes into the power module, and see if that kills the blower or not. If not, then that wire is indeed grounded somewhere. If it does kill the blower then the problem is either in the power module or the control unit in the dash as described earlier. You should be able to pull the supply fuse to kill the blower for the time being (I don't know which fuse however).
Roland





Hi Lloyd,
Unfortunately I don't have the factory shop manual for the Eagle or its companion models. But I do have the Haynes and it points out that rather than a resistor block the ATC unit has a solid state blower power module with what appears to be a couple of transistors and a heat sink that provides for 14 different fan speeds. That is probably the cause of your problem. It is located near the blower motor and as with the resistor block of the conventional unit the module is inserted in the air duct near the blower so that it's heat is dissipated by the action of the blower. You can best find it by looking at the right hand end of the unit, under the dash (you will probably have to remove the lower right dash insulator panel below the glove box for access) to locate the blower motor and you will find that its power wire is plugged into the module in question. There you will find a couple of screws that hold the module to the duct. Maybe you can find an electrical component that has gone bad on the module and replace it, otherwise find a used one at a wrecking yard, or buy a new one from a Chrysler dealer.
But even before you do that, you might want to remove the ATC control panel and check the fan speed rotary switch to make sure that it hasn't burned out, rather than the power module. But I don't have a circuit diagram to show what that switch is supposed to do electrically. I believe that the unit can be removed once you take off the bezel that surrounds the console. Ideally, if you tried measuring the resistance across the pins of the fan switch it should vary with the position of the knob. If not, then that switch would be my first choice for replacement.
Let me know what you find out, please.
Roland