blower motor stays on
slhogue
08-28-2009, 09:48 PM
1995 oldsmobile 88 my blower motor continues to run after shutting off ignition i have replaced the module and checked the fuses the only way i can get it to shut off is to unplug the blower any help would be greatly appreciated
moscow913
08-29-2009, 01:11 AM
Year and make of car?
I'm going to assume this car has auto temp controls. Normally, the blower module is the culprit. The blower module/motor have constant 12 volts. The blower module is made up of diodes and diodes normally only allow voltage one way. Diode goes bad, voltage runs both ways and blower stays on with key off. But you say you replaced the module. The blower module? Either you have a bad blower module, or depending on the year and model of the car and in rare instances, the relay is stuck closed. 99% of blower running with key off is the module. Of course there's always wiring problems.
Good luck
I'm going to assume this car has auto temp controls. Normally, the blower module is the culprit. The blower module/motor have constant 12 volts. The blower module is made up of diodes and diodes normally only allow voltage one way. Diode goes bad, voltage runs both ways and blower stays on with key off. But you say you replaced the module. The blower module? Either you have a bad blower module, or depending on the year and model of the car and in rare instances, the relay is stuck closed. 99% of blower running with key off is the module. Of course there's always wiring problems.
Good luck
slhogue
08-29-2009, 11:31 AM
is there any way to check the module to see if it is bad? i really hate to invest in yet another one if it is wiring or the relay.
thisnametooktolong
08-29-2009, 05:44 PM
it could also be the high speed fan relay with a shorted/welded contact even if the ran is not running on high. Try Pulling the relay from under the hood
moscow913
08-30-2009, 01:19 AM
You'll have to check for correct power to the module. Make sure it isn't getting power where it shouldn't. Make sure it isn't grounded from the blower side either.
Unplug the module-does the blower stop? I'm assuming it does. If it is a new module, I'd say you have wiring issues or a control head fault. Pretty rare that a new module is bad.
Unplug the module-does the blower stop? I'm assuming it does. If it is a new module, I'd say you have wiring issues or a control head fault. Pretty rare that a new module is bad.
Automotive Network, Inc., Copyright ©2025
