Since it was 95 degrees here the past two days, I tried putting the a/c on in the Evo today. Engine rpms jumped a bit, but no cool air, so I bought a can of refrigerant/gauge to see if the system was charged. The first thing I noticed was that when I turned the a/c on, the rpms would jump, the fans would turn on, but the compressor wasn't spinning. The gauge also showed that the system was overcharged, but since the a/c clutch wasn't engaged I didn't know whether this was accurate. Either way, I let it be since I didn't want to overcharge the system. This morning before I went out, I decided on a whim to check it out again. This time, the clutch engaged and the gauge showed a low level condition. I was able to get a little refrigerant in there and the car blew cold air for a few minutes, but I wasn't able to get the system full. Not sure if there is a leak or if something is wrong, but I went out to get more refrigerant, and now everything is back to the way it was - clutch won't engage and gauge shows high pressure.

Any ideas? A/C systems aren't really my forte. Thanks for reading the essay.

 

Abev...

There's a HUGE thread about AC problems a few down from this one. It'd be worth digging into but the short of it is...

1. Your AC functions on a pressure switch, so if the pressure isn't correct, it won't engage the magnet on the compressors clutch.

2. If you're hearing an increase in engine RPM, I would wager the electromagnet is working, but perhaps the clutch isn't aligned, or gapped properly. Again... check the thread. Try getting under there and tapping on the clutch on the compressor with a wrench or ratchet handle when it should be engaged, and see if that gets her to spin.

3. I know that many people refill systems with the over the counter cans, myself included... but so you're aware... those are essentially designed to take a functioning system, and keep it in good order (I'm reaching a bit here), not to take an inoperative system, and restore it to working order. To do this, you really do need a manifold setup.

4. Regarding the leak... you can get a can of the refrigerant that has the dye in it, and then run it, and check for leaks with the glasses/light/whatever combo they suggest.

My advice would be to:
1. Read the huge multi page AC thread to get the gist of what I'm on about.
2. Hop under there with the sucker running, and give it a tap to see if she'll spin...
3. Consider the repair advice in that super thread.
4. Inspect (look, listen, feel) for leaks in the system. Easier said than done in some cases, but part of the game unfortunately. Repair/replace as necessary.

Hopefully that'll get you started.

 

Thanks a ton for the reply. I skimmed the forums for an a/c-related thread but I guess I just missed it, so I'll definitely check it out. Thanks for the ideas and for pointing me in the right direction!

 

Abev... apologies. I must've been asleep at the wheel.

There are a couple of threads about it, but they weren't just below yours lol.

Start with this one...

https://www.evolutionm.net/forums/ev...ng-advice.html

If you have other questions... post up!

 

Look at the youtube vid as well. Someone takes a wrench and wacks the compressor with it. Clutch engages soon after. Later on he said he had to re-shim the clutch to OEM specs. For myself, I just bought a used compressor and replaced it. Took about 30 mins of my time and I didn't even have to remove the LICP for it.

 

I re-shimmed mine as well... but mine wasn't working simply because of lack of pressure in the system. I had a leak in my condenser. Swapped that, reshimmed the clutch, charged the system, and she fired right up.

 

A note of advice, regardless what the over the counter A/C refill gauge tells you, often times people over charge the system and it will not engage. Evo AC system is very sensitive.
In this case, if you keep the AC on and purge the system, the compressor will kick on.

 

It might be a shim-related issue. When I give it a nice whack, the clutch engages, so I'll check that out. Thanks for all the help guys