My a/c fan or another fan that I don't know will not stop blowing. I turn off my ac unit. I turn off my heater. I even shut off my car it keeps blowing. I had to unhook my battery to get it to stop. When I attached my battery again it starts blowing again. Please advise.

Well thinking about the problem there e a flap in the vent pipes to shut off theatre and ac unit perhaps something has got in the pipe and stopping it closing or perhaps your heater control is US and needs replaceing . ( but I take it you have turned your heater to cold )

You may find a reset will solve this annoying problem. The problem you have is the GM heater control unit has lost it's calibration, which can happen from time to time. The way to reset it is, start your car and turn your heater off, and shut off the car, pull out the keys. Then with vehicle off, disconnect the battery, (or batteries if it has two). Let sit for 10 minutes, then re-connect battery. Get in and start the engine, DON'T touch anything, let the heater control unit re-calibrate for at least 40 seconds, (by the clock), then try turning on the heater.
Good luck!

check ac control unit if you replaced blower module and if your sure fan works

It sounds like your AC unit could be overheating or even damaged.

AC units have a sensor that will turn them off automatically to prevent damage from overheating. If there is an insufficient amount of air flow, the unit will heat up, and then eventually turn off.

When the car is moving, more air is forced over the unit, likely keeping it cool enough to run, however, when the car come to a stop, it loses that air flow, and quickly heats up. Thus, the AC would work while the vehicle is in motion, and overheat and stop when the car is stopped and idling.

However, the AC unit could be completely blown. The cold air while moving could be just a case of air being forced into the car. Think of a house fan, the fast the wind blows on you, the cooler it gets.... Thus, it could be an illusion that the AC is working when car is in motion, when it really isn't.

Hope this helps.

How old is your battery and if it's over 2 yrs old get a new one also when u get out of the car make sure u turn the fan all the way off then it won't try to turn on

verify the fuse first!! the blower is located behind glove box, see it under it and only need to remove 4 phillips screws!

Hmm, a problem that I have not encountered before. My best guess is that some component within the heater setup is getting overheated and then it shuts off to avoid further damage. If the heater runs each time you start the car and then turns off during your travels, then this might be the case.

Secondly, there are circuit breakers located in the fuse box. These are silver and are about twice the size of a standard fuse. Unlike a standard fuse that blows once and is done, circuit breakers get hot and "trip". After they cool down the connection is made again. Look to see if a circuit breaker (sometimes labeled CB) is in the fuse box and serves the heater. You may want to get a new one.

sounds like a shorrt to 12v to me. The wire is hot and the fan is shutting off because the blower is bad, getting to hot, it will bind, causing over amperage.

hi lisa, this looks like an electrical problem, if out of the blues the ac unit stopped working. check the following
ac fuse inside your car ac fuse outside under the hood check fuse for fan as well
hope i helped thanks

i would deff check the relay i had a problem with my relay going out on my 04 but i just ran my fan to a togle switch so i can turn it on and off when i want it on when im in dead stop situations like traffic and also when your ac is on the fan has to be on or your ac will cut on and off to keep your car from really over heating in a hurry if your not moving, but i also run my car at the track and it helps to keep it cooler when racing down the drag strip.