ac on/ ac off/ ac on/ ac off

[rocs1stz]

Ok, I have a major problem. When I purchased my 00 z28 last October the ac was working. Last month it stopped working. I tried to add more freon to it, but the gauge indicated that it was full. I ordered a new sensor to replace the one on top, between the firewall and the receiver drier. With that having no change I replaced the relay under the hood, but that didn’t help either, so I put my original sensor and relay back on the car.

I then took it to a mechanic who said he “placed a jumper” on the system and the compressor started working, for (1) day. Then the mechanic vacuumed down the system and added more freon and the compressor started working again, for (1) day. My wife just called and said the compressor is working again. What is it that I should be replacing?

[Vahomboy]

Sounds like a leak to me. You can pressurize it with nitrogen to find the leak by spraying a leak finder solution it. Then vacuum down and recharge. (Short version of how to fix) If it is cycling on and off, probably due to a low charge and the low pressure switch is causing it. The low pressure switch is probably what he jumped out the other day to make the compressor run to charge it.

[rocs1stz]

do i need to replace the pressure switch as well. hope the leak isn't coming from the compressor. i priced them at AAP and they wanted $341.00.

[98redM6]

I had the same problem after I got it recharged and had installed used low-mileage components. It stopped after about 3-4 days and I'm pretty sure there was some moisture trapped in the system. Been running fine for about 1 month now.

[rocs1stz]

thanks, i'll try that tonight.

[HMFDZ28]

What you need to do to see if there is a leak is to put it under a vaccum for at least 20 min. If you see a pressure leakage well its time for the dye. Do not jump the pressure switches. There is most likely a clogged orifice tube. Its between the low pressure and high pressure side, inline.