Bad A/C Compressor?

[IsaacJB97]

Gentlemen, new to this forum and I have a question regarding my a/c. So yesterday, after years of solid performance, the air conditioner started blowing warm. I didn't think anything of it so I went and bought some R134 this morning thinking I was just gonna do a quick refill and that'd be that. Hooked up on low side and I'm reading full pressure. That's when I decided to sit and watch the compressor for about 10 minutes. I didn't check before because I honestly didn't want to entertain the nightmare of an a/c job. So yeah, after 10 minutes of watching the compressor, it never cycled on. Do I have a bad compressor or could it be something else? I know it's probably bad but just looking for some input before I get knee deep into this job. Thanks gentlemen!

 

[Spaznaut]

Ran into this same thing on my 4.0 '95. I'm about to start searching on checking the electrical because the compressor turns freely with a 5/16" socket but won't cycle when I try to fill it. I want to make sure I'm getting a signal before I buy a compressor.

 

[IsaacJB97]

Compressor is good...I think. It turns freely by hand. I haven't put a multimeter to it yet to see if it's getting power but, if it is, I read on another post about bypassing the pressure safety switches by jumping the clutch manually. How do I do that?

 

[bobflood]

There are several things that can prevent the compressor from turning on - low pressure switch, high pressure switch, WOT switch. First, jumper power from the battery directly to the compressor and see if that turns it on - that will let you know if the compressor is working. Then, turn on the circuit and work back down the circuit from the compressor to each of the switches with a test light (not a meter) looking for voltage. If you have the EATC instead of the manual controls, there is a relay on the circuit board that develops bad solder joints that can also prevent the compressor from running. That's why you use a test light instead of a meter - the meter will detect voltage even thought the bad joints wont pass enough current to operate the compressor (or turn on the test light). Good luck.

 

[IsaacJB97]

Alright so I jumped the compressor and the clutch engaged. She was low on refrigerant so I dumped a 22oz can of R-134a in. Ran up to the parts store and got a new WOT a/c relay just for yuks. Got home, put her in, cranked the a/c and nothin. I got nothin. My system does have an automatic button on dash but I never use it. I just crank it manually by pushing the Max A/C button and scrolling the knob to Max/On. Where else should I check now? Do I have a bad switch, either low or high side? My electrical in general has been acting funny so would I maybe have an ECM issue? Thanks!

 

[IsaacJB97]

Also, something I'm thinking of this morning that I failed to mention last night, when I initially took the low side cap off to fill the system, after only two or three full turns of the cap, it blew off with a lot of force. It didn't just kind of pop off, it shot off of there like a rocket! Even after the fill, there was still a significant amount of pressure coming out of the low side fill/service port and I had a pretty tough time getting that cap back on. That just doesn't seem right to me.

 

[1998Exp]

The cap is a "secondary" seal. Sounds like the check valve underneath is leaking. They are very easy to replace -- ask for the tool at a parts store.

 

[IsaacJB97]

I appreciate all the help but I'm done trying to track down this issue. This weekend I'll put in a new accumulator for $30. That should take care of the busted low side service port and the check valve that seems to be shot since the low side service port cap keeps blowing off. While I'm doing that is there anything else I need to replace? Thanks!

 

[IsaacJB97]

I apologize. To clarify, is there anything that is normally replaced when doing an accumulator job? Just the normal little things? Thanks again gentlemen.