C7 AC Compressor Issue - Help!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,561
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From: Cape Coral, Florida
Easier just to check the load side of the relay…terminal 87 that goes to the AC clutch relay….if you probe terminal 87 of the relay with test light connected to B+ and if the test light illuminates I know that that part of the circuit is good from the relay down through the windings of the clutch to ground…if any of the inputs are missing ECT, AC pressure sensor, Ambient Temp sensor the control side of the relay will not work…also just checking for 12 volts at the compressor isn’t good enough…you may have 12 volts but can terminal 87 carry the current ??…you need to load the circuit and check with a headlight bulb as a substitute for the clutch.
Burning Brakes
Joined: Jan 2019
Posts: 954
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From: Louisiana
Easier just to check the load side of the relay…terminal 87 that goes to the AC clutch relay….if you probe terminal 87 of the relay with test light connected to B+ and if the test light illuminates I know that that part of the circuit is good from the relay down through the windings of the clutch to ground…if any of the inputs are missing ECT, AC pressure sensor, Ambient Temp sensor the control side of the relay will not work…also just checking for 12 volts at the compressor isn’t good enough…you may have 12 volts but can terminal 87 carry the current ??…you need to load the circuit and check with a headlight bulb as a substitute for the clutch.
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
OP needs to find a diagnostic shop that can diagnose this…he said the refrigerant is full so I’m assuming someone had AC manifold gauges hooked up and the pressures are OK.
Thread Starter
Cruising
Joined: May 2024
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Certain dash wiring ??…HUH ??…to say the compressor is “visually” not working tells me the relay is NOT working !!…dealership techs are CLUELESS so find a diagnostic shop that can diagnose this accurately…they understand electrical circuits not only on your car but ANY car…is the AC clutch engaged with the AC on ??…do you know what the AC clutch looks like when it’s engaged ??…it takes me 5 minutes to check the AC Clutch relay…all 4 terminals…all that is needed is a 12 volt test light.
Thread Starter
Cruising
Joined: May 2024
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It's not that I didn't want to take your word for it, I just wanted to make sure I wasn't ordering the wrong part because I couldn't find mention of the corvette year being compatible. I appreciate the help though!
Drifting
Joined: Dec 2013
Posts: 1,519
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From: FL
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,561
Likes: 4,029
From: Cape Coral, Florida
DEFINITELY not a body shop…auto-electric shops do good at electrical diagnostics…diagnostic shops are good at everything…general repair shops and dealerships just replace parts and HOPE they get lucky !!…1 in a 100 are somewhat capable…where do you live. ??…I may know a diagnostic shop near you…if you find a shop with “auto diagnostics “ in their name I would use them !!…they use advanced diagnostic equipment like a labscope and others….here is a good YouTube channel you can watch so you can see how a real pro diagnoses cars…Bernie Thompson is probably the best diagnostic tech in the country and one of the top instructors too…he and his company develop and manufacture diagnostic equipment…he doesn’t GUESS !!
