I'm a noob when it comes to A/C so any help is appreciated.
I live in AZ and A/C is a MUST... My system worked flawlessly until yesterday. I had just taken a long trip from Phoenix to Tucson (about 250 miles round-trip) and the system worked just fine. Today when I started up, the A/C does not work...Only blows warm air.
The clutch on the A/C compressor does not engage. I read this can be from a number of factors (low refer, high/low switches malfunctioning, bad compressor, ECM malfunction, etc.) I noticed what looks like a high-side pressure switch, behind the compressor, in-line about 3" back from the compressor on the high-pressure line (the smaller of the 2 tubes coming from the back of the compressor). This "switch" is screwed on to a Schrader valve and has 3 wires coming from it (Red, Black and Brown). This switch had backed itself off about 1-2 turns and had oil sprayed all over it. It seems like it had backed off just far enough to allow the R-132a and oil to leak out slowly. I tightened the fitting.
I then tried to refill the R-132a using a refill kit. I have never had problems with the system until today, so since I found the "leak" and fixed it, I thought a refill would do the trick... As soon as I hooked up the gauge to the LOW side adapter (the smaller of the 2 fittings above the evaporator, just to the side of the fuze box) I got a reading of 140psi.
The instructions said to immediately stop and not add any R132a, and seek professional assistance.
What could cause this pressure? Is it a faulty Low-Side or High-Side switch? I have never had any problems with the compressor, nor does it make any weird noises. I have tried to bypass the high-side switch using a short wire (shorting red to black, red to brown, black to brown, and red to black to brown). Only when I short all 3 does the A/C control allow A/C...Otherwise it only bypasses A/C. Still no compressor.
Is there a way to force the compressor to engage? On the front/top of the compressor, near the pulley are 2 small wires - Blue and Black. Do these engage the clutch? How should I wire these to get the clutch to engage? Short across or add 12V to either pin? If I do get the compressor to engage, should I worry about the 140psi, or will that level itself off after it runs for a while?
Where is the low-side switch? Could this be faulty and allowing the low-side pressure to get too high, causing the system to shut-down to protect itself? I'm really hoping it'* not the compressor...I'd hate to go thru the hassle of recovering all the R132a, replacing the compressor, vacuuming the system, recharging, just to find I'm back at square 1...
Ideas? Thanks for the help!!