Z28Freak86

Well my ac wasnt blowing cold air like it should be, so i got a can of refridgerant and was ready to refill the system. When i put the can to the low side (car running and ac on max), the gauge read 140 psi. Well of course thats way too much, but then i noticed my ac compressor never kicked on. My question is what could be wrong the the compressor not kickin on and how can i get it workin again. thanks

Z28Freak86

new update. checked the relay, and when i jumped b1 to b4, the compressor finally kicked on and ac operated normally. the relay checked out to be ok, so the problem is elsewhere. i also checked the other slots, and b3 had 12 volts with both ac on and off and b5 had 0 volts with both ac on and off. where do u think the problem could be?

n2ceptor

Clutch cycling switch??????????????

chevyinside

Is there any codes from the a/c system in the computer ? It'll prevent the a/c from turning on

Stl94LT1

Jump the relay and check the pressure while the compressor is running.

JP95ZM6

140 with a/c off and a hot engine compartment is pretty normal. That should be enough to turn the a/c on. Check the sressure sensor in the accumulator. I don't remember if it's 2 wires, or 3. If 2 wires, you can jump across the terminals of the connector and the a/c should turn on. If so, likely a bad sensor.

Testing the 3 wire style requires the right resistor across 2 of the pins, I think.

Z28Freak86

k im gonna try some of ur suggestions today see what happens

scottso

This thread was good reading when I was looking into my system...

http://web.camaross.com/forums/showt...ylcling+switch

Z28Freak86

Ok that post got me a good understanding of the system, but i still have 2 questions. im almost positive its the switch, but the parts store online says its only for 2 connectors (i have 3 on mine, a red, grey, and black). where can i get the 3 connector, and lastly, is there any way i can bypass the switch to see if the compressor kicks on?

JP95ZM6

The 3 connectior kind is a transducer (pressure sensor) as opposed to a simple switch. I have jumped them before, but I don't remember the details. You need a normal voltage to the signal wire (gray). I don't remember what is normal, but if for example it is 1 volt, and the power wire (red) has 5 volts, you need the right resistor to give you a drop to 1 volt, then use that to jump from power to signal. However, without knowing the current, you can't easily calculate the resistor value. You could start with a high value like 100k, then 10k, then 1k, and so on down to a few ohms until you get the right voltage, or the compressor turns on. If you can scan the car (something with all the data, not Freescan) you can read the refrigerant pressure. The reading should match your gage if the sensor is OK. Somethong between 40 -140 psi should turn it on. All values are approximate.

BTW I see you have a 95 Z38. I said accumulator above, but that would be on the low side, in in an orifice-tube system. '95 Z28s have a TXV system, in which the 'aluminum reservoir' is on the high side, and called an R/D (Receiver Dehydrator).

Hope that helps. You have several suggestions above. Let us know what you find.

Z28Freak86

well heres what i got. i dont have resistors handy, but i did use a 5:1 tranformer that got me one volt to the grey wire, and the compressor kicked on. so i guess its the switch.