evildave

Found a few links on the forum that suggested my blower control module could be faulty (fan runs flat out when key out of the ignition, and can't turn off the AC when running normally) i have the dual climate control.

After about an hour and a half laying upside down in the snow with a dislocated back i managed to get the control module out.
Is there a way of bench testing it? or should i just buy a replacement?

lucky131969

Actually, the best way to test it is in the car. Auto or manual A/C?

evildave

I have the auto A/C

lucky131969

Then it needs to be in the car to evaluate it. Exactly what is the problem?

evildave

with the car running i tried changing the mode so it wasn't trying to defog and pushed the off button for the A/C. the yellow light flashed a couple of times but the air con came back on, even when i tried turning the fan speed down it always defaulted back to A/C on.
The car was ok when i bought it (just before xmas) and i believe the previous owner garaged it. It's been out on my drive for a couple of weeks now and we've had a fair bit of snow and cold weather here in the uk, the only way i managed to stop the blower motor running was to pull the 30A maxi fuse in the passenger footwell.

lucky131969

Ok. What you are describing is a very common failure with the blower control modules for auto climate control GM cars/trucks. There is one additional check you could do with a DMM if you like. The blower speed control signal input is on pin C of the blower control module connector(tan wire). The voltage on this wire will increase and decrease as the fan switch on the control panel is depressed accordingly.

lucky131969

evildave

That's great, thanks for your help :-)
Will order a new module and see what happens.
My first post and a friendly fast response, this forum rules!!
Cheers,
Dave