why wont cooling fans turn off

My cooling fans have always worked normally...turn on when hot or ac turned on. I fixed my ac a few months ago and they still worked normally. Then my ac broke again, a leak in a line so lost the freon.
I haven't fixed it yet, but the fans run anytime the car runs now. What gives? This is even with climate control unit turned off completely.
With it getting cooler outside and my fuel trims being off cause the car runs so cool now, id like to fix this. Hurts my gas mileage too.

dreww wrote:

My cooling fans have always worked normally...turn on when hot or ac turned on. I fixed my ac a few months ago and they still worked normally. Then my ac broke again, a leak in a line so lost the freon.
I haven't fixed it yet, but the fans run anytime the car runs now. What gives? This is even with climate control unit turned off completely.
With it getting cooler outside and my fuel trims being off cause the car runs so cool now, id like to fix this. Hurts my gas mileage too.

Congratulations I've never heard this one before and I kinda doubt anyone else has... It occurs to me to check electrical lines in the vicinity of the AC line leak. The leak did not happen to be by or freeze onto wiring for the fan or a temperature sensor? Do tell.

Albertj

albertj wrote:

dreww wrote:

My cooling fans have always worked normally...turn on when hot or ac turned on. I fixed my ac a few months ago and they still worked normally. Then my ac broke again, a leak in a line so lost the freon.
I haven't fixed it yet, but the fans run anytime the car runs now. What gives? This is even with climate control unit turned off completely.
With it getting cooler outside and my fuel trims being off cause the car runs so cool now, id like to fix this. Hurts my gas mileage too.

Congratulations I've never heard this one before and I kinda doubt anyone else has... It occurs to me to check electrical lines in the vicinity of the AC line leak. The leak did not happen to be by or freeze onto wiring for the fan or a temperature sensor? Do tell.

Albertj

You know this isn't even my craziest electrical problem...read my transmission post thread.

I remember right after the ac broke again, I got under the car and checked the plug into the line coming out of compressor...think its one of the pressure switched. At this time the fans worked as normal still but when I unplugged the switch, they turned on. Makes sens as that opened the circuit just like turning on the ac. But sometime after that they just started doing their own thing.

I really should just strip this car down and sell all her parts on here. I would if I had buyers for most the stuff already lined up.

dreww wrote:

albertj wrote:

dreww wrote:

My cooling fans have always worked normally...turn on when hot or ac turned on. I fixed my ac a few months ago and they still worked normally. Then my ac broke again, a leak in a line so lost the freon.
I haven't fixed it yet, but the fans run anytime the car runs now. What gives? This is even with climate control unit turned off completely.
With it getting cooler outside and my fuel trims being off cause the car runs so cool now, id like to fix this. Hurts my gas mileage too.

Congratulations I've never heard this one before and I kinda doubt anyone else has... It occurs to me to check electrical lines in the vicinity of the AC line leak. The leak did not happen to be by or freeze onto wiring for the fan or a temperature sensor? Do tell.

Albertj

You know this isn't even my craziest electrical problem...read my transmission post thread.

I remember right after the ac broke again, I got under the car and checked the plug into the line coming out of compressor...think its one of the pressure switched. At this time the fans worked as normal still but when I unplugged the switch, they turned on. Makes sens as that opened the circuit just like turning on the ac. But sometime after that they just started doing their own thing.

I really should just strip this car down and sell all her parts on here. I would if I had buyers for most the stuff already lined up.

- or just replace the switch. no drama or surprises here. With a car past 10 years old/150,000 miles there are a number of one-time maintenance things to do and this is just one of them. I am surprised (pleased) that my pressure switch has not crapped out yet.

Albertj

So you think a bad pressure switch is causing the circuit to stay open? They are the OEM switching so you may be on to something. Ill try to pick one up at, gotta go to Autozone anyways.

dreww wrote:

So you think a bad pressure switch is causing the circuit to stay open? They are the OEM switching so you may be on to something. Ill try to pick one up at, gotta go to Autozone anyways.

You ought to be able to test the switch to see if it changes state under pressure, you think? Ohmmeter? watch out for the whirling pullies and whizzing belts...

Albertj

Ok I got an ohmmeter...excuse the ignorance but how exactly would I test it? Unplug it, stick ohmmeter prongs in either pinout and check readings with ac switched on vs off? Guessing reading on meter should change when I do so and if it doesn't then bad plug?

Is your car throwing a P0128 code by chance? My Regal does that with the 160* stat in there. The PCM isn't happy with how long it takes my car to get to temp and after a few cycles it triggers this code. The fans stay on all the time and when I reset the code the fans turn off. Don't ask me why these cars turn the fans on when the car is not getting up to the temp... the PCM thinks it should. Makes no sense... however, that's what happens. :/ CEL will not light usually with this code. I pick it with the Interceptor gauge.

Not trying to lead you astray. If it's this, it probably makes things easier.

No code like that. I got a 180 stat but no EGR so warmup does take longer but it wont throw codes for that

dreww wrote:

Ok I got an ohmmeter...excuse the ignorance but how exactly would I test it? Unplug it, stick ohmmeter prongs in either pinout and check readings with ac switched on vs off? Guessing reading on meter should change when I do so and if it doesn't then bad plug?

You're right, and be VERY careful of moving parts.