Testing AC Clutch

[offnpublic]

I've got the Matrix service manual from this site (thanks for that). As I've read the Matrix and the Vibe use different ac compressors. The service manual states to test the clutch, run leads to two terminals on the wire that powers the clutch. Well the Delco (i think it's a Delco) compressor in the Vibe only has one terminal. I believe the service manual is referencing the Denso compressor in the Matrix having two terminals. How does one test the clutch in the Vibe? I ran a lead from the positive on the battery to the one terminal on the Vibe clutch, thinking that the clutch must be grounded through the compressor. Nothing happened. That could be because my clutch is not functional as I predict after testing all the other factors of the system or it could be because that is not how to correctly test the clutch. I did this with the car not running thinking I could hear a click of the clutch trying to engage. Does the engine need to be running? I just want to make sure that I am testing it right before making the switch. I do have another compressor in route.Thanks for the help in advance.

[TONY TAT2]

Looking at the compressor on my 09.I came to the conclusion it's a "internal" lock up, no magnetic lock up as a external clutch.

[joatmon]

helps to know what year, but I'll assume it's somewhere in th 03-08 range or else you'd likely take it in for a warranty repairThe wiring diagram from the 03 GM service manual shows only one wire (12V) going to the compressor, with ground through the chassis.

Attached files

[joatmon]

The 03 service manual has detailed diagnostics for the circuit, but doesn't include a step to test the AC clutch itself.I looked at my 03 Vibe, and with the engine off, the belt keeps the AC pulley from moving, but I can turn the end plate by hand. Then, when I put 12V on to engage the clutch, I can hear it clunk, and can no longer turn the compressor end plate by hand.The connector for the one wire isn't that easy to get to down in there, so what I did was pull the AC clutch relay out of the underhood fuse block and put 12V on the output terminal socket. Shoved a wire into the connector, used my right hand to touch it to the battery + terminal, left hand on the end of the compressorHere's a pic of the AC clutch relay socket with an arrow indicating which terminal is the relay output (the one to put 12V on to engage the AC clutch for testing)

Attached files

[offnpublic]

Exactly what I was looking for. Thanks Joatmon. I was out of town this weekend and will test this out tonight or tomorrow. Very true on space issues with the connection on the clutch. Thanks for the heads up on the relay terminal. That small space was the reason I tested it with the car off, didn't want my hand down there with the pulley spinning. Many thanks, I'll post up my results as I get them. My spare compressor will be here next weekend and I'll try to document that.