badgertr6

87 NA
I recently replaced the AC compressor and condenser because the PO damaged them in a accident. Installed "guaranteed" used units, and took the car to a local AC shop for a fresh change of R134. They said the system is tight, and they were able to charge it, but I can not get the compressor clutch to engage. I know I am getting 12 volts at the spade connector to the compressor when AC button is pushed. I suspect a clutch issue, but if I "hot wire" the clutch by applying 12 volts to the clutch from a battery while the car is not running, I do see the clutch move inward toward the compressor body. When I button everything back together, and run the vehicle at idle, and turn on the AC, I hear no click, drop in engine speed, or anything like that.

So just because I can see the clutch move when voltage is applied, could I still be dealing with a bad clutch?
Any other ideas?
Thanks...

Charlie

Try applying 12 volts to the compressor from a battery while the car is running and the AC button is pushed and see if it cools.

thomasmryan

it is possible to read 12 volts on a meter but not have enough current to create the field required. it might be dirty/pitted contacts in the relay.

Beckman technologies had a probe that show current capabilities but I don't see it listed on their page.

badgertr6

Ok
removed the factory 12 volt connection
attached test leads to the clutch wiring
started car and turned on AC in cabin
energized the clutch with a spare battery and test leads
Cold Air!
Also noticeable drop in RPM.
You are on to something Charlie!

What next?

badgertr6

Bad Relay?

Charlie

I would look at the relay. Like Thomas said the contacts could be burned and you are showing 12 volts but don't have enough amperage.

badgertr6

OK - Solved - Put a different relay in from my parts car and all is well.

Thanks for the feedback....