Help! Please. 2004 Pontiac Grand Prix


My vent fan will not stop running when I turn off my car. The fan speed switch does not change speeds but I can tell it still turns on and off. The ac light turns on when I turn the switch on and goes off when I turn the switch off. The fan speed does not change though and stays on. The mode switch still works and will change the air from vent, to defrost, to floor. The temp button still works too. This just happened and I had to unhook my battery to stop the vent fan motor from running and draining my batter when I turn the car off. Does anyone know what the problem is? PS This is not the radiator fan it is the vent fan that blows air into the car. Even with the key out and the alarm set the fan still blows.


My first thought is an electrical short somewhere. I’d check the visible grounds in the engine compartment, make sure they are okay, but you might need a wiring diagram to see where the grounds are for the fan motor. Good luck.


Thnx 4 hlp. I’ll try this. I’d rather do anything myself then go to the dealer.


I suspect the problem with this is the solid state speed control for the blower is shorted and is suppling continous power to the blower motor. If you have the type of speed control that is variable then you have one of these controllers.

If you want to try to fix this yourself then you should be able to find the controller by following the wires running from the blower to the controller. A new unit may cost around $115 dollars for the part. You can also remove the connector to it so you won’t have to remove the battery cable. You could also remove the fuse for it to disable it.