I have a 91 deville and the heater blower keeps running even after I turn the car off. From nosing around the net it seems that the control module needs to be changed. The problem is that I have no idea what it looks like or where exactly to find it. Can anyone be of any help?

Not sure of the exact details, or which cadillac modle it was on, but I recently read that climit control module is by the blower motor. Sorry, I was looking for information on the body control module, which is different, so I didn't pay a whole lot of attention. The article mentioned something about having to cut the housing around the blower motor, and I got the impression that the module was between the housing and the blower motor. There wasn't any description given, but the article recommended replacing both the module and motor at the same time. Something about the blower motor not puting out the correct amps consistantly causes the module to go bad. I wish I could be of more help, but maybe this will get you started in the right direction.

I have a 91 deville and the heater blower keeps running even after I turn the car off. From nosing around the net it seems that the control module needs to be changed. The problem is that I have no idea what it looks like or where exactly to find it. Can anyone be of any help?
Doubleouch: Had the same problem on my 89 Eldo, Blower motor kept running even with car off.. The module sits inside the blower ductwork, but can be easily removed right from the top, has, I believe 3 0r 4 small screws, its right on top of the blower ductwork back by the firewall, you have to unplug it first, and its a little hairy getting your hands to it. Once you unscrew it, then gently lift it out. You can probably more easily find it by feeling for it when the blower motor is running. They are fairly expensive at the dealer. But I picked one up at the junkyard for $25. They had 3 of them all marked good, and it is still working. Not really a hard fix. Just take your time looking for it and I'm sure you will find it. Good Luck! TJ

Thanks all I found it under the relays and fuses against the firewall. I followed the wire from the fan back to it. I found a picture of it from advanced auto parts. They call it an atc module. I'll check a junkyard tomorrow. Part is 100 bucks online. I don't even want to know what the dealer wants.