Well, took it to the shop today and the checked to see if there was any charge to it. I was good. Service tech was able to get the compressor to come on by jumping the contact points at the dryer connectors and compressor started and it began to cool down. But as soon as the jumper was released, compressor off and no more cold air. I showed him the location of the relay and the #12 fuse. beyond that, looking at the wiring schematic on Volvowiringdiagrams.com, he was more or less lost and admitted that old a car was beyond his ability. At least I know I can get it to come on. Any way of bypassing the a/c relay like the OD relays on automatics? Any suggestions or directions?

Thanks everyone.

Hello Bob

I recently had a problem with the wife's car, I had 12volts at the wire feeding into the compressor, but it would engage intermittently. I was in process of tracking down a new compressor when I discovered the true problem. One of the bolts to the A/C bracket had started to back out, it was the same bolt that held the ground wire from the battery cable. Once I tightened that up and checked the others all was fine. Take a look.
--
Bruce S. near D.C.

Let me get this straight. Something is not clicking right in my brain on this picture.

You took it in to check the charge and it's good. If so, that switch he jumpered around should have been closed already.
That circuit from inside the car provides power to the compressor through that switch. If you run very low on gas it's suppose to be open.

Are you sure he did not apply power, from the battery, on one side of that connector to run the compressor?
From what you are saying the switch was open. There is either a very low or no charge. The switch in the dryer out there can be defective, despite the refrigerants pressure in the dryer.
It's rare but happens!

When the compressor ran did you see bubbles for a split second in the sight glass?
After that short time it should go clear with liquid passing by. It should look to be slightly magnified between operations.
I advise that you use a bright flashlight to observe this action down in that tiny glass.

Did he by any chance have a gauge on the system to observe the low side?
How cool did it get a chance to cool down to?

On one side of that connector out there should be 12 volts there. This is after starting the engine and allowing a delay relay to close after about ten seconds. The alternator voltage output starts the timer.

This relay on my '86 went bad and I jumped it out. It's located on the lower right side of the console behind the side panel.
I decided I didn't need any kind of stinking delay relay. I needed cooling now and it failed on me while on a trip! I rather jump, the relay than have my wife jump me....? In her mean way! (:-)

You need to find out if there is power on the thermostat switch as those leads can pop off easily if you had that front off for any reason.
From the thermostat the power goes down to the relay and then out to the dryer switch.
If the relay does not close the A/C is dead.

Do a little poking around. If you find the relay and its socket you can bypass it there.
I do not recall the specific terminals but power from the thermostat is one color wire. The other one's color should go out to the dryer switch.

Hope this helps you get the idea of where the failure is.

Phil

Isn't there a low pressure switch on that thing? Usually part of the drier.

Is it separate from the dryer itself or incorporated in it?