I have a 02 F150, When I turn off and take out the key. The A/C heater system turns on full blast. What to do?

I've taken it to the Dealership and of course they wan tto charge 1000.00 durning Christmas!! But they said your GEM Module needs to be changes out and your fuse panel is damaged. Yet everything from the light,horn,wipers,seat controls all work perfectly..the only problem is the A/C turns on full blast when keys are taken out of the truck. What do I do?

I have a 02 F150, When I turn off and take out the key. The A/C heater system turns on full blast. What to do?
can you get to the harness?if you can,then hook up a kill switch to your heater switch.that will work till you get the money to get it fixed proper.
Reply:Well if you dont really need your ac you can unplugg the blower motor so that it stops blowing constantly. But its most normally the blower motor resistor that has gone bad when that particular problem occurs. I would think they would have checked that but if they didnt its a 40 dollar part and pretty easy to change if that is whats wrong with it. Thats located under the passenger side of the dash right beside the blower motor. Hope that helps. Good Luck!!!
Reply:It definitely isn't your resistor module so don't change that. If that was the problem you would usually have no control over blower speed. I would strongly suggest you stay away from the dealer, they are the worst to solve problems and charge lots of $$$ and you get no satisfaction. Most dealer "mechanics" aren't qualified to work on problems. Oil changes are about the limit.It appears you haxe a peoblem in the ignition circuit, in particular in the key switch. It will take some work with a volt meter and continuity tester or vom as they are commonly called. When you turn off the switch something is connecting your heater to a 12 volt source. It is probab;y within the switch itself. A wiring diagram and some electrical know how would be worth a shot before taking the switch apart or replacing it. Ask the dealer or better the shop boss if there are any technical service bulletins about this condition. These are from the factory and report known problems that they don't want us to know.
Reply:get a chevy truck