Aux fan...when and why does it come on?

[jteuton]

I've just noticed the aux fan has never ever been hooked up on my car and my car has never ran hot. I hooked it up and it never came on.....so whats the deal with it???

[Mantis88LX]

only comes on if u are sitting and ideling for a few minutes

[jteuton]

ok...but isn't this the purpose of the larger fan.....so it needs to be called a twin setup because they both are suppose to come on together cause mine doesn't....the bigger one comes on but the smaller one sits there....is it for the a/c or something???

[offthahook]

I thought they both came on when the AC is running or when the car is "hot" enough that the thermostat kicks on the fans. Is there a time that only one of them comes on and one stays off????

[jteuton]

Mine must be broke but hell it doesn't run any hotter.....lol

[rocky2]

One fan is for engine cooling(bigger) the other is for a/c core cooling,only comes on in conjuntion with compresser coming on.Bet your air don't work...gm cars are junk but have the best ac systems, seen beaters that air still work