Air compressor clutch not kicking in

[RJ Malanum]

Hi guys, I've been at this problem for a while now and not much people seem to know what's happening to this VY.

Simple symptom is, the clutch in the AC compressor isn't kicking in. And the compressor was not getting any power supply to it.

I've tested the relay by bridging the supply volts to the compressor. That tricked the compressor to kicking in. Although even with a brand new relay, the compressor wouldn't kick in on its own. Also when it did kick in, the gas in the car was not circulating, only maintaining 24 degrees in the cabin.

I next tested the high pressure switch. It showed me 5V for two of the wires and the third was earth, so the wiring was good. So I bridged the two wires with the 5V signal but the compressor still didn't kick in or cycle.

I'm thinking of replacing the high pressure switch but I was wondering if there could be anything else to check before I do.

Also, can anyone explain the circuit path of the high pressure switch to the compressor?

Thanks heaps if anyone could help.

 

[edals]

When was the last time it was gased ? May just be very low and have a leak. They won't work until it has a certain pressure.

 

[mpower]

I had a pressure switch issue, it's cheap as - worth a go.

If you bypass it though and it still doesn't work can only think it might be a relay or something.

 

[Jxfwsf]

If it didn't get cold when you had the relay point bridged & compressor running then it's low on gas, this would be why it won't work.

 

[Luke Johnson]

I have same problem after changing engine, loom, ecu and bcm. Compressor will not kick in. If there are no bolts to the compressor loom plug, what can cause this? How do I manually bridge the connections to test?

 

[RJ Malanum]

I serviced the gas before thinking that same thing. I gassed it up to the recommended 850g of gas and replaced both Schroder valves, but still no difference. And all the relays for the compressor is new.

 

[MYVESSV8]

tx valve maybe

 

[Jxfwsf]

So what were the high/low pressure readings before you re-gassed it?
What are the differences when it's running now and gassed up?

Could be tx valve or it could be the compressor, these variable displacement compressors do fail, if you have the equipment to re-gas it then you should have the knowledge to diagnose it first.
Schrader valves were replaced, was it evacuated correctly? Or did you not check the pressure and simply dump gas in there.... after watching a few youtube videos.

 

[Luke Johnson]

I next tested the high pressure switch. It showed me 5V for two of the wires and the third was earth, so the wiring was good. So I bridged the two wires with the 5V signal but the compressor still didn't kick in or cycle.

I'm thinking of replacing the high pressure switch but I was wondering if there could be anything else to check before I do.

Also, can anyone explain the circuit path of the high pressure switch to the compressor?

Thanks heaps if anyone could help.

What is the easiest way to bypass switches and relays to identify an electrical issue with the a/c. I have got it regassed properly but still no go, so there is an electrical issue that it is not getting the signal to 'kick in'. What should I bypass to get it going?