DANdeMAN

Thanks DR, good advice, I may do that.
Thanks Dave, no I don't have the .doc I don't have the original Jim moores CD.
Bill, you already posted that link, thanks.

So, lets forget about jumping the clutch, my gut feeling is it is the HVCA relay as the problem started with the defross from hell setting mistake.
I'm very good doing meticulous/precise work so if it is the relay, I will most likely change it myself. ..The thing I need to know, is how to check the relay itself.
So please do not esitate to walk me through the steps of testing the relay and what I need to test it with!
Thanks a million to the brave man/woman who will accept the challenge.

SharkSkin

See if you're getting +12V on either of the freeze switch terminals when you try to activate AC. If not, and fuse 9 is good then the relay *might* be kaput.

j.kenzie@sbcglobal.net

Dan,
Even money on low refrigerant which prevents clutch engagement vs. bad relay which prevents signal to clutch to engage. You have to check for 12V at one side of the freeze switch or we'll never know. My guess is low freon.

Bill Ball

I did? Please check again. The first link was to John Pirtle's write-up. The second is Wally Plumeley's troubleshooting guide. Wally's has more electrical information.

Oh, I see Dave posted the link to Wally's guide! OK, well, it's so good that it deserves reposting.

DANdeMAN

Oooops, you'r right...I was sure it was you.

DANdeMAN

This will be my weekend project....note to self : get a good voltermeter!

Thank you!

docmirror

You don't need a real accurate meter, just something that has all the functions you will use;

http://www.harborfreight.com/cpi/cta...emnumber=30756

Doc

DANdeMAN

OK, got the voltmetre today.
Checked if I had power at low coolant switch and I do.
Jumped the wires there and the fan whent on but the clutch did not. Is that OK? and should I still check the freeze switch?
Also, does that mean that the relay at the HVCA head is OK?

What next? Thanks

Bill Ball

Pull the wire to the compressor - there is a brown plastic spade junction block hanging free just above the front compressor that joins a small wire from the harness to a wire that goes to the comrepssor. Pull the connector apart by removing the compressor side wire from it. With the AC switched on see if there is 12 volts coming from the harness lead. If there is, turn off the car. Check the clutch by providing the wire that goes to it with 12 volts by wiha jumper wire touched to the jump post on the passenger fender wall. If the clutch enagages when given 12 volts from the jump post but does not engage when the harness power wire is reconnected and the AC is on, then the relay is providing 12 volts but not enough amperage to engage the clutch and the relay is suspect.

DANdeMAN

Thanks Bill, will check that ASAP and will keep you posted...

SharkSkin

You may have shorted the wrong switch, the High Temp switch is supposed to kick the fan on. The low pressure switch is nearby, on the side or bottom of the dryer IIRC.

The first connection after the relay is the freeze switch. Checking there will tell you whether you need to look for the problem in the passenger compartment(no 12V @ freeze sw) or engine compartment(12V @ F.S) or the freeze sw. itself(12V on only one terminal of the freeze sw.)

SteveG

Dave:
Just to be sure, you are saying, are you not, that you must have 12v from BOTH terminals of the freeze switch?

SharkSkin

Well, not exactly *from* both terminals. The current flows in one terminal and out the other. The switch should normally be closed, allowing the +12V to flow from the HVAC head to the low pressure switch. So, if the HVAC relay and the freeze switch is good you should see +12V on both sides of the freeze switch when the switches/sliders are in a position that calls for AC... unless of course the evaporator is frozen.

DANdeMAN

First pics is where I jumped yesterday when the fan started..
Second is today. On the left wire no juce; right 12V+. Is that what you ment Dave? The ignition and AC was on with engine not runing and with engine runing was same thing...So I guess it must be the relay right?

SharkSkin

Not sure -- I have to run off to work, and I'm less familiar with the physical layout of the wiring on later cars. The freeze switch is up in the cowl area near the windshield wipers, under that plastic cover.