A/C stopped working, no power to Compressor

[jdjonesdr]

Thanks, MovieTvet,

Well, I went out to look under that cover, and there's only one relay in there, and it's a biggie. I forgot to count but I believe it was 8 or 9.
The cover has molded inscriptions describing what it's covering, and it indicates the big relay was for the fuel system.
Here's the page out of the manual that shows where my a/c relay is apparently located. (note it idicates the location at the center of the dash)

You must be registered for see images attach

Also, on another parts website, this is what they have as the A/C relay

You must be registered for see images attach

In any case, I'm going to pull the center cover on the dash tomorrow and see if those relays are hiding in there.
I know there are also some relays behind the glove box as well from when I changed the resistor for the fan.
The positive wire on the compressor plug is green with a white line, so I'm hoping I find a relay with the same wire.

It's amazing how these parts go bad after time even though I have a low milage truck.

 

[movietvet]

Thanks, MovieTvet,

Well, I went out to look under that cover, and there's only one relay in there, and it's a biggie. I forgot to count but I believe it was 8 or 9.
The cover has molded inscriptions describing what it's covering, and it indicates the big relay was for the fuel system.
Here's the page out of the manual that shows where my a/c relay is apparently located. (note it idicates the location at the center of the dash)

You must be registered for see images attach

Also, on another parts website, this is what they have as the A/C relay

You must be registered for see images attach

In any case, I'm going to pull the center cover on the dash tomorrow and see if those relays are hiding in there.
I know there are also some relays behind the glove box as well from when I changed the resistor for the fan.
The positive wire on the compressor plug is green with a white line, so I'm hoping I find a relay with the same wire.

It's amazing how these parts go bad after time even though I have a low milage truck.

That tab on the relay indicates that it is remote from the fuse/relay box. Make sure, when you find that relay, that you check the "drag" on the female connectors to the male spades.

 

[jdjonesdr]

So here's the latest and greatest.

I located the compressor relay under the dash, Located behind the glove box.

When I turn on the A/C, the relay clicks, so I know the switch in the console is good, and the relay is good.

Just to be redundant, I stuck a new relay in there, and it clicks too, so I've eliminated the console switch and the relay.

I've got power going to the high-pressure switch on the accumulator.

I put 12V to the compressor, and it's good.

No voltage in the plug that goes to the compressor, so I've got a problem in the wiring.

I'm guessing that a wire screwed the pooch when I installed the new alternator and went from 12 to 14 volts.

Next will be bypassing the factory wiring between each component and see if I can narrow down which wire is causing my headache.

Stay tuned.

 

[movietvet]

Ok, trace it down. For future reference, the switch at accumulator is a "low pressure" switch.

 

[jdjonesdr]

Ok, trace it down. For future reference, the switch at accumulator is a "low pressure" switch.

"That" switch. lol

I tested the old relay and found it wasn't good. But, the A/C still didn't work with the new relay.

Fast forward to today.

I went out to muck around with it today. Opened the hood, and noticed the trouble light on the hood was much brighter than it's been. That screams "ground" to me.

Started the engine to warm it up, and of course, the compressor is back and doing its thing.

I'm convinced it's probably a dirty ground connection somewhere.

As an aside, I also noticed my fender-mounted trouble light has stopped working. Looked at the in-line fuse carrier and both contacts are grey. The fuse is good, but 12V is not getting past it. Another bad connection.

Anybody wanna bet that when I clean those contacts, my light will start working again?