A/C Clutch will no engage

I have a 2000 XJ, 4.0, 4x4, auto, etc...and the A/C clutch will not engage. I have read through tons of different forums and posts, done pleanty of research, consulted my Haynes manual, and cannot seem to figure out what is going on. I have added more R134 and made sure it is within the recommended range, I have checked the A/C relay and fuse on the passenger side of the engine compartment, and all has checked out okay. When I have the engine running and turn on the A/C, I can hear a "click" and the RPMs go down a little when that happens, but the clutch does not engage. Any thoughts?

How did you check the relay? I would pull it from the socket and look at the diagram on the side. I don't recall if those use the large or small relays, so check the terminal that is main power into the relay for voltage with key on. Next power up the output terminal of the relay while watching the clutch, it should click and engage- engine doesn't need to be running. If it doesn't engage the clutch, push in on it and see if it engages. If so the gap is too large and a shim will need to be removed.

If you still have nothing, ohm the wire from the outlet of the relay to the clutch connector. If you have continuity then the clutch magnet has gone bad, verify with an ohms reading, infinite ohms or OL is bad.

Testing from the relay eliminates the rest of the AC system, so if the clutch engages right off the bat when you first jumper it then look at the charge level and cycling switch.

Thank you very much. I will give it a shot when I get home.

Just wondering if you made diagnosis Duckfan? My A/C clutch only engages sometimes, typically when the engine is cold. Go Ducks!

Im having the same problem as the OP, i have checked all the same stuff as him and also at first when i turn air on it was engaging and would blow cold for a min or so then get sorta just warm(ish)...and now when i turn it on the clutch doesnt engage at all, This heat is killin me so any other ideas would be great!

I had a similar problem with my 99, in which the clutch itself had gotten rusty. It would engage at first, but poorly, and then as it heated up it would stop engaging, go warm, etc. I "fixed" it with a plastic hammer. I figured if the clutch was toast anyway I had little to lose. You have to be a little careful not to bend anything, but basically what I did was to whack it gently until it freed up. When it finally did, it ground out a cloud of rust dust for a bit, then calmed down and has worked fine ever since.