Hi,

A/C was working great on my 96 for a few months after a recharge. Then, on a long drive last weekend, I noticed it getting balmy in the cab. Checked my pressure with gauges, all good. No leak. Noticed the compressor clutch was "walking", but not engaging. Figured I needed to remove a shim. My problem was that I pretty much destroyed the clutch getting it off. While shopping for a new clutch I saw I could get a whole new compressor for not much more, so I went that route. Old one had 200k+ on it. Also went ahead and got a new dryer/accumulator and idler pulley. Got the system drained, new parts in, held a good vacuum, sucked in some r-134a to can pressure (I guess), and... compressor wouldn't cycle on to suck in any more. Bummer.

I've had the old system empty and didn't have much trouble filling it back up. There is only one wire to the compressor on a 96, and it's got power. I tried grounding the compressor body to the battery, nope. I tried applying power to both pins on the low pressure switch connector. Nothing. I tried "jumping" them with a paper clip, but didn't apply and voltage. Should I try that? That isn't how switches work, right? The only thing I can think of is another shim issue, but just seems unlikely on a new unit. Also, I guess it is possible I got a lemon (from China. Shocking, I know).

Any suggestions?

Thanks!

 

If everything has power available where/when it is supposed to have it, then your relay and fuse should be good too. I've seen on how-to videos that all compressors ship with way too much oil, so you are supposed to drain all of it and only replace the same amount that was in your old one. Seems like not all compressors ship with that instruction.

I need to watch this thread. Going to be doing the same replacement in my 1996 XJ soon.

Additional questions: Is there a best brand of A/C oil? Found one reference that this year system needs 100 weight A/C oil.

Also need to figure out if my system already bled the refrigerant out, I don't see green through the sight glass anymore.

 

Updates.

So I tried some things again today. I DID get the compressor jump-started. I thought something was wrong with it because I was getting power to the compressor connection via my test light. However, When hooked straight to +, it engaged and sucked in some refrigerant. So that's good, but even after a full charge (32oz on a 96) my compressor still won't cycle in it's own. With my multi-meter, I get 12 volts (well, 13.6 or something) at the compressor connector, but only like .01-.03 amps, so that's not going to engage the clutch. So now I am completely confused. Can't really follow the circuit because it disappears into the harness. I tried "jumping" the low pressure switch every way I can think of, which only kicks it into high-idle, but it did then when connected too.

If I can't figure this out, I'm toying with the idea of "permanent" hot-wire job, with just an on/off switch in the cab. I realize I'd lose my low pressure safety switch, but at least I'd have A/C. Do compressors run all the time on a normal system? Somebody tell me why that's a terrible idea...

 

Fixed it.

It was the relay... Go figure. Usually something simple when you think you've got to tear the whole system apart.

 

I shall celebrate today as the day I got one right!

 

You are right about the oil. Mine came with 8oz in it. Dumped it out and put in 2 oz of new PAG oil and a little UV dye just in case. Good call on the relay.