That is the ground control for the relay. That is how the ECM turns the A/C on and off. The ECM has decided not to turn it on for one reason or another. It monitors switches and other thing to makes it's decision and it's not satisfied with something it monitors.

Answered by Wrenchtech (expert)
14,749 answers provided

Thank you. I figured it was a grounding source since the schematic showed no other ground for the circuit. After reading some other information on the topic, I came to the conclusion that I needed to check the A/C thermostat. After diagnosing that part, I found out that it was not functioning correctly and by shunting a bypass around that, the A/C kicked on. I'm glad that I had read further, otherwise I was about ready to replace the two relays located just behind the front bumper: the A/C compressor clutch relay and the condenser fan relay. Had I done that I would have still had the problem.

Thanks for your reply as it verified my thinking on the subject.

Regards,

JP

Response from jrparish831
1 question asked

Make sure you don't leave that thermostat bypassed because it will cause the system to freeze up and that will damage the compressor.

Answered by Wrenchtech (expert)
14,749 answers provided