I drive a 2004 Chevy Monte Carlo and the A/C is usually fine. However, this car has gone through 4 blower motor resistors.
What happens is that, randomly while driving or when turning the A/C on (it will go out even if the A/C is already on) the A/C just suddenly starts blowing full blast. HOWEVER, if I turn the A/C dial to off, it only blows air (not cold or hot) and the resistor does not get heated. However, if I turn the dial to any of the settings, the resistor begins to warm up and the hot/cold air starts blowing.
When I shut the car off, the air continues to blow. The reason I think the problem is the resistor is because, in the past, when I have replaced the resistor, this problem is fixed. However, I am now sure this is a chronic issue somewhere else - but I cannot even begin to think where.
Also, should the resistor even be heating up if it were the problem? Am I replacing the wrong part? I would think that, if the resistor were bad, it would either A) Not pass the resistor and no A/C would blow OR B) Blow at high speed and completely bypass the resistor.
Because I know when the dial is at the highest setting, the wiring diagram shows that the current will bypass the resistance.
Can anyone give any insight as to what might be causing my resistors to appear (or really) go out?