Odd A/C Issue - Please Advise [Archive] - GrandAmGT.com Forum


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06-29-2011, 03:25 PM
Hello. First post here. Found many a good topics over the last few years. Thanks.

Odd problem here. Just yesterday my A/C just stopped working in the middle of the day. Got home and watched for clutch movement. No movement. Checked relays/fuses and heater control board inside...all good.

I can jump the terminals on the AC Compressor relay in the engine compartment fuse box and get the clutch to kick in and start producing cold air inside. I cannot seem to get the low pressure switch to jump though.

Any ideas on where to go? I have sufficient refrigerant pressure while the engine is running and it makes wicked cold air but I can't seem to get the AC compressor to kick on without jumping the relay terminals.

Thanks for any advice.

06-29-2011, 05:21 PM
have you checked the relay? tested it with a meter?

Put an reader on the car and make sure the computer knows that your making a request for cold air.

that would be the place to start.

06-30-2011, 08:27 AM
If you checked the relay and it's good but when you jump the relay the A\C works, the relay must be bad. Switch it with another relay in the box and see what happens, most of the relays are the same.

06-30-2011, 02:40 PM
Relays test good. Fuses are fine. All pigtail connectors are fine.
Low pressure switch not broken. Getting voltage to the ac compressor relay and able to jump terminals 30/87 to get the clutch to kick in and start the ac.

I think I've narrowed it down to the BCM not sending the a/c request signal through to the relay to drop the voltage and get the relay to close and kick the compressor on. According to the haynes wiring schematic I've narrowed it down to the BCM not sending a signal to the relay.

I've taken the fuses/bcm out and letting everything sit while I cool down inside.

I'll update and when I see if it is the BCM needing a reset or if that isn't the case, I'll be popping by the pick and pull and finding the most dry least destroyed grand am to pull a new (used) BCM out (they run for 20 bucks) and see if that works.