Hi Guys. Im having a issue with my 2004 Grand Prix GT. I took a 2 hr drive to Peoria, IL yesterday and on the way going my car was fine. When I started heading back I notice my air was blowing extremly hard like a fan and the air was off. Then When I turned my car off the air was still blowing and would not cut off. I knew that if it blew all night it would drain the battery. Which it did, I had to get a jump this morning but the air still continues to blow while the car is off. Anybody know what it could be. Also two weeks ago my keyless entry stopped working, tried changing the battery didnt work. I thought i needed it replaced but today it starts working and now the air isnt working. Im so confused....

Pull the fuse to keep from draining your battery.

I know the 97-03 models with automatic climate contorll used a "blower motor module" that had constant B+ running to it. Some guys were having issues like yours where their fans would run after they shut the car off and took the key out. Replacing the Blower Motor Module solved their problems.

You have a 2004 though. I'm not sure if the HVAC system is designed the same or not.

Do you have automatic climate controll?

When the GP was redesigned in 04, they got rid of the blower resistor even on manual HVAC models and went with a blower module on all HVAC systems.

Tblake is correct in suggesting you change your blower motor module, as that is what causes your problem almost 100% of the time on 04-up Grand Prix's.