96 K1500 AC Compressor Question

I cannot get the compressor to engage and tried to jump the low pressure connector. Is there a way to check the AC Relay?

Thanks,

Is there any pressure in the ac system lines?

If you jumpered the correct connector, it should engage the compressor.
I would jumper it and measure for 12 volts at the clutch.
Or even jumper 12 volts direct to the clutch.
Bob B

I jumpered the connector plugged into the backside by the lines going to what looks like a small sending unit, should I testing the one by the clutch up front?

I also put a new relay in today with no results!

I jumpered the connector plugged into the backside by the lines going to what looks like a small sending unit, should I testing the one by the clutch up front?

I also put a new relay in today with no results!

I believe the connector is back near the firewall.
On the side of the receiver dryer.
Like I said, you can put 12 volts directly to the compressor clutch to get it to go and take in the new freon.

bob b

If it is completly out of freon the system will have to be vacumn out before it will take enough freon for the high and low pressure to be right and cool and operate properly.

I found the switch, replaced it and the pump is now working, but it is making a very loud "wining" noise. I think either it needs oil or it is toast?

Run it a couple days if it doesn't quiten down have a tech listen to it cause if it does need oil in the sysytem it is a pain and without specific tools like a freon recovery unit , vacumn pump , then ac oil , makes it near impossible to do on your own . Cause to put oil in a unit it has to be emptied and oil added then vac'ed then freon put back in .

Run it a couple days if it doesn't quiten down have a tech listen to it cause if it does need oil in the sysytem it is a pain and without specific tools like a freon recovery unit , vacumn pump , then ac oil , makes it near impossible to do on your own . Cause to put oil in a unit it has to be emptied and oil added then vac'ed then freon put back in .


You can add oil yourself, all you need is an oil injector (like a big syringe with a screw-in plunger) with a low side fitting. Fill with PAG oil, connect to the low side service port, and turn on the A/C. The system will suck the pressure down to 20-40 PSI, making it fairly easy to force the oil in.

I wouldn't run it at all if you think it's low on oil, a couple days could be enough time to destroy the compresor. But before you add oil, make sure it has leaked some. It will be wet and dirty around the leaking area. If it's not low on oil, don't add any, too much is bad too.

All I can do is advise I was trained by GM to do it a specific way and it has stuck ever sense , there are other was to do things Just as good .