a/c stays engaged with switch turned off

[mark c]

what causes the a/c compressor to stay engaged when the car is running and the a/c is turned off. it is a 1998 gt

 

[wmburns]

Some "possible" causes might be:

• Bad CCRM
• incorrect CCRM for the model year
• Faulty AC mode control switch that's still applying power even in the off position. Note, the AC is supposed to run in the defrost position.
• Wiring short

To test the AC mode control switch, test for key on power at the low pressure clutch cycling switch Purple wire. With the AC in the off position there should not be power. There should be power with the AC in the on position.

If the power is correct at the low pressure switch, then suspect a possible CCRM issue. However more tests are needed to confirm.

 

[mark c]

it is the CCRM . i was running the a/c and it started smoking from under the hood on the passenger side . exactly where the CCRM is located, electrical smell.so it has fried a relay in the unit . thanks very much for the help.

 

[wmburns]

it is the CCRM . i was running the a/c and it started smoking from under the hood on the passenger side . exactly where the CCRM is located, electrical smell.so it has fried a relay in the unit . thanks very much for the help.

The CCRM is located inside the right hand (passenger's) fender well. It's necessary to remove the fender liner to get better access.

If this were my car I would start with a visual inspection of the CCRM and go from there. Check the connector for evidence of water damage or over heating.