1993 Cadillac STS continous run mode

CCS7

MEMBER
1993 CADILLAC STS
V8
FWD
AUTOMATIC
120,000 MILES

A few months ago I had a spug wire arcing between the blower motor and a plug wire. I replaced the plug wire(s), and it appeared to be running fine. In the last couple of weeks, I returned to my vehicle from the store only to find that my defroster unit was running though the vehicle was turned off. The interior controls work fine from changing from one status to another, but I'm unable to change fan speed or turn off the system from the control panel. I currently unplug the wire(s) to the blower/switch unit to stop the blower from constantly running (ignition off). My question; is it the blower unit switch or the electronic climate control unit? Would it be ideal to replace both units to keep one from shorting out from the other?

1 Reply

FACTORYJACK

MECHANIC
4,159 POSTS

You have a power module located in the top of your heater case, under hood. It has three 7mm head machine screws that hold it in the case, two wire connectors, one two wire(only has on going to it-red) and one four wire. Disconnect the two wire connector with the large red wire and your blower should go off. It is more than likely shorted, and in some cases is a result of high current load of blower motor. I would replace power module.