Home stretch on the AC
 

Its been 5 years with no AC- so many other things to do and so little $$$.

It all started with an intermittent AC, I went in for an R12 re-charge but that was a no go so they just slammed in something, maybe r134a, it lasted about 2 weeks before the AC died again. While trouble shooting i replaced the freeze switch and the AC relay (thanks Dr Bob and Dwayne) but the system stayed dead. I finally bit the bullet and got the compressor rebuilt and then installed it, a new receiver dryer and expansion valve and lots of green o-rings. So, fully charged with the correct 860g of r134A I pushed the AC button to get....no cold air. I checked things out and the AC clutch worked fine with a clean 12v from the jump post- cold air! I tracked back and checked out the pressure switch, then pin nine, then the freeze switch then the AC controller. I had previously removed the AC relay from the climate controller and replaced it with the radio shack relay (thanks Roger) but decided to do it all again as I am possibly the world's worst solderer. Finally, the AC works, nice and cold, don't know what various wimps were thinking when they dissed r134a, I had -15c at the centre vent, plenty cold....Hmm, I looked at the evaporator and it was nice and snowy white but still the compressor spun merrily. I removed the freeze switch and tested it and it seemed to work fine. In the end I took it to the AC guy and he tested the AC but with a critical difference, he ran the AC with the doors and windows closed and this time I had the blower boot on and the plastic cover thing in place. This time the compressor cycled off as expected, still a little cold at about -2c before shut off but I'll adjust the freeze switch and that should be sorted big Yay!, apart from...the small green drips from the bottom of the (rather expensive) rebuilt compressor. Somethings are just a total pain to get sorted once and for all.

Well done! I overfilled the oil on mine so it isn't that cold, and the hi/lo switch is broke, but it is better than 95f temps!

I took all of my A/C stuff out of the car, which required removal of the entire interior and resealed and foamed the HVAC system.

Put on Griffith's kit which includes a new compressor, barrier hoses, all o-rings, and the oil used in the compressor.

I replaced the expansion valve and put all of those items in and now I have working A/C in my 81.

I also added a second relay in a way different to yours.

I took the power line that would activate the clutch and made it activate a relay so I could fuse the clutch and take all of the strain from head unit's relay.

I was one of the lucky few who still had a good relay in the head unit after 32 years.

I will tell anyone never to go as deep into the system as I have because you will lose all of your sanity in the process. No wonder A/C shops told me they don't work on 928s.

Nice job on reviving your A/C, it is one of those features that you can't live without in warm climates. May the 928 A/C gods be ever in your favor ;)