Need HELP with '80 AC Switch/Fuse

[gilbybarr]

Hi there.....I am new to this forum, even though I have had an Avanti for 5 years now so thanks in advance for your help. I am selling my 1980 Avanti II and buying an '89 Convertible. The '80 is in mint condition with everything working EXCEPT that the AC compressor clutch is not engaging. The AC is blowing cold and working fine when we jumper wire the clutch....but it wont engage on its own with the AC switch in the dash "on". We added 3 cans of freon as I had never used the AC and not kept it charged. But even after adding the freon (a valuable comodity these days!!) it still didnt kick on unless it was jumper wired. I am not a mechanic, my buddy was doing the work.......he is good but even he couldnt get the thing to kick in....he said there may be a fuse or a low pressure switch that may be bad somewhere. Can any of you all out there offer up some help and advice? This is the one thing left to get corrected before I sell her. Its an original car other than the motor was swapped out for an LM1 GM Crate motor 12 years ago. Thanks very much in advance for HELP that you can offer! Ed in Knoxvillle.

Oh......my email is gilbybarr@chartertn.net

Edited August 17, 2008 by gilbybarr

[MikeValent]

If I understand the system (I have 3771, an '83 and its a/c setup should be the same as yours), there are two dash (actually vertical console) "switches" that must be connected properly and working right for the a/c to blow and blow cold. The fan speed rheostat should be the bottom of the two and have three wires attached t it. One power, one ground, and the third a jumper to the adjustable thermostat. That switch in turn has one wire going further into the console and presumably providing either power or ground to the clutch.

I can't remember which is power and which ground, but the thermostat gets power (or ground) from the fan switch (from a lug that is not controlled by the rheostat). Are these wires in their proper places? When you jumpered the clutch, did you jumper directly from battery to clutch? That wouldn't indicate whether the switch wiring was properly set up.

If your fan speed switch is the round "infinite adjustment" type, the lugs marked 1 and 2 take the black and yellow wires coming from inside the console. Attach lug 3 to the thermostat switch with a jumper (should be a black wire if there is one already there). You may need to swap the wires for lugs 1 and 2 - I can't remember which goes where.

If the fan speed switch is of the 3-speed type that Nostalgic Motors sells it also has three lugs, two on one side and one on the other. Attach the yellow and black wires to the two lugs on one side. Attach the jumper wire to the single lug on the other side. Again, you may have to swtch yellow and black wires to make it work.