So I manged to fix the rough Idle on my 95' Jimmy 4.3L by cleaning the EGR valve after stumbling across this forum and figured I'd try fixing my A/C as well. After trying to research the subject on here, I was a tad overwhelmed and figured a thread specific to what I'm dealing with might help

So my compressor doesn't kick in and I don't have power to the wire on top of it and I noticed the end was damaged. I found what I thought was a splice point warped in electrical tape, but it turned out to a little white box I had never seen. I've included some pictures

What is that white box? Can / Should I cut off and replace the clip ? would that be a possible fix. I checked power to the fuse and it was good, but I'm not sure which of the 3 relays on the firewall is A/C or how to check one for that matter. I haven't been able to check the freon level yet, but was hoping it was electrical and will kick on. Thanks!

 

Somebody has been there before you, and they obviously didn't know what they were doing The white "box" appears to be a splice connector, (it did not come from the factory like that). There should be a diode from the dark green wire to the black wire near the clutch connector. If the two wires are connected together, without the diode, the wires will get hot, and eventually pop the fuse. Looking at the clutch connector, it appears to have been hot Check with a boneyard for a replacement connector, and the diode. Trace it back from the connector and you'll see/feel where the diode is. Keep going a few inches and snip it off. Can't be more than ~$5 or so.


The black wire at the clutch field connector, (on the compressor) must have ground to it at all times. The dark green wire from the clutch cycling switch, (on the accumulator) supplies voltage to the clutch field when low side pressure is above ~42psi. If the refrigerant level is low, (or empty) the cycling switch will not allow the clutch to engage. This is a safety feature to protect the compressor. By the looks of things, the AC probably quit working, (due to being low on refrigerant). Someone that didn't understand the circuits, tried to "fix" it, and messed it up even more. Once you have the electrical end of it repaired, you'll need to use a manifold gauge set to check pressures, and if they are low, you'll need to find and repair the leak. The system will then need to be drained, evacuated, and recharged. DON'T just add refrigerant, as it can do permanent damage to the compressor. The refrigerant system is very sensitive to the amount of charge: too much will destroy the compressor, too little and it will not cool sufficiently, or the compressor may not come on at all. We can walk you through the repair process, but if you are not comfortable doing it, take it to a professional. AC and electrical work is expensive because not everyone understands it.

 

Thanks for the info,... before I read your reply I jumped the low pressure cut of switch and the compressor worked so I tried adding some coolant (though I don't think my gauge was working as if was all over and quickly abandoning the effort. However my A/C worked after doing this, though not super cold it was putting out cold-ish air and I really added almost no freon

So I guess my questions is, do I need to have it drained and properly filled still. Can I drain it myself ? Can I just go buy a new gauge so I know where I'm actually at for pressure and go from there. Do i still need to worry about and diode? and should I remove that white box if I install the diode. Thanks

 

Yes it needs the diode.


Clutch Cycling Orifice Tube systems, (CCOT) do not have a sight glass to check the refrigerant level, and checking pressures will not tell you how much refrigerant is in the system. The ONLY way to know how much refrigerant is in the system, is to drain, evacuate, and recharge with the proper amount, of the proper refrigerant. As mentioned, the system needs to have the correct amount, within 2 ounces, or it will not perform properly. Using single cans of refrigerant is not nearly accurate enough, not to mention, they are dangerous.


EDIT: gauges are used for diagnosing problems, NOT for checking refrigerant level.

 

Alright thanks, I won't run it for fear of wrecking a good A/C system, and I'll try putting in an diode. What am I looking at to have it evacuated and refilled?

 

Check with some local shops for an estimate. Typically 1.5 to 2.0 hours labor plus refrigerant, (just under 2 pounds) to drain, evacuate, add UV dye, recharge, pressure test and leak test.