Vincenza V

Hi guys, I need you a/c help. I had my evaporator replaced at an Ice Cold Air chain about two weeks ago. I had a leak that was making th compressor run fairly constantly. That problem is fixed.

I had my air compressor replaced, accuumulator, orfice tube, and flush and fill at a local reputable mechanic one year ago today (I have a two year warranty on the compressor)

My problem is the a/c works.....sometimes.

I have brought it back to the shop that recently did the evaporator. problem being, everytime I bring it to them, the system is working fine, and they can't trouble shoot it when it's working perfect they said.

Each time it is not working, i pop the hood-the compressor is NOT coming on. I don't know if it is a loose wire somewhere, bad vacuum, or bad compressor (It was new from Advance Auto)

What "tells" the a/c compressor to come on? An electrical. or vacuum thing?

I really want to get this figured out myself, then if needed-the shop can fix it (If it's their fault, fo free. If it wasn't related to the Evap, then I will see how much it will cost)

Can you hard wire the compressor to come on or is that asking for problems?

Do the a/c switches in the cabin go bad commonly?

Note, for the past two weeks of the a/c working intermittently, when it was on, it would work great and be cold. ONLY today, did it work great, and then go warmer (not cold).

-I can't feel any cold air around the defrost, or floors.

-The tech that did the evap said I have a newer chrysler blend door, and it looked recently replaced

-He checked the high and low pressure switches

djb383

Presuming it's still under warranty, take it back to the shop and tell them to keep for a day, drive it to lunch, chase parts with it, etc. Most likely the best ones to diagnose the problem is the shop.

Knucklebuster

Could be a defective high pressure cutoff switch or a defective low side activate switch. Both are in the system loop. The compressor gets a signal to turn on when the low side of the circuit goes above about 40 lbs. AND the high side is not above about 230 lbs. There is also an outside temperature sensor which moves these numbers depending on the outside temperature. In addition the compressor will not activate when the low side is below about 10 lbs. This is to protect the compressor from burn-out if there is no refrigerant in the system. The other possibility is that the clutch is not fully engaging due to wear of the clutch material. there is a fix for this involving the removal of a shim in the clutch package.

weebur

I recently watched an interesting YouTube video of a guy troubleshooting his intermittent compressor problem. With the engine running and the AC switch on his compressor would not run. He tapped on the compressor with a plastic mallet and it started running. He did it several times and every time is began running. After removing the shims behind the clutch it ran fine. Apparently the air gap was just a little too big. Your gap may be on the borderline, even with a new compressor.

Vincenza V

Thank you guys. I was able to run the XJ over to Icer Cold Air in a period of it not working. Thankfully, it didn't come back on before they saw it as it did last few times. The fouind out the "Tough ONe" Advanced Auto compressor was bad! It is exactly 1 year old today. Two year warranty thank goodness.

I'm having them install one now.