Mechanics

AIR COND HEAT SYSTEM

1993 Cadillac Deville • V8 FWD Automatic • 125,000 miles

Have 93 sixty special Cad. LED on ac won't come on. AC blows thru defrost until led comes on. Have noticed when it's cold or humidity is low (not often down here) it will work after car has run for awhile. System regulates to 75 degrees and will work once LED lights up. Fuel gauge does sometimes does the same. Appreciate ANY help I can get.
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Trulove
June 18, 2011.



It sounds like you have a low refrigerant issue. Open the hood and start the car. While the engine idles, turn on the AC. See if the clutch engages on the compressor. Check the relays in the system under the hood. High humidity areas cause electrodes to corrode. You might want to use some rubbing alcohol and an old toothbrush to clean the electrical contacts of the relays, switches and connectors.


Rivermikerat
Jun 18, 2011.
I think your issue is electrical in nature and would have to be troubleshooted while the problem is present.


Wrenchtech
Jun 18, 2011.
Where are the relays, switches and connectors to clean? Thx


Tiny
Trulove
Jun 20, 2011.
Refer to the attached image. The relays are (facing the engine from the front) at the right rear of the engine compartment.

The compressor coil connector is on the front of the compressor behind the pulley. The switches are the ones on the dash you use to control the A/C.


Rivermikerat
Jun 20, 2011.
The a/c and fuel panels are controlled by the bcm. One can short the other out. You need to remove both panels. Then unplug the a/c panel connector to see if the fuel panel lights up. If no plug the a/c panel back in. Then remove the fuel panel connector and watch to see if the a/c panel lights up. When either panel lights up the other one is bad. Gl


Cadieman
Jun 21, 2011.