A toggle switch would work. The easiest is probably to interrupt the wiring at either the low pressure/cycling switch at the accumulator (either the blk/wht or dk grn wire) or the wiring at the high pressure switch behind the compressor (lt blu or dk grn/wht wires).


George

 

Thanks George. I have been pulling the electrical connector from the compressor when I want to keep the AC off while working and diagnosing (right on top of compressor). Is that the high pressure switch you're talking about?

 

There are two sets of wires at the compressor, the compressor clutch power (dk grn and blk) and the HP SW (dk grn/wht and lt blu). I suggest interrupting the latter because its lower power.

George

 

When the AC on my 1965 ford wouldn't shut off I ordered a new thermostatic switch. It had the electrical at one end and a thin tube at the other, which I pushed into the old hole, where it monitored the temperature near or at the evaporator. The new one switch measured the temperature correctly and shut off when it got cold enough.
How much different could it be in 50 years...

 

I really hope you don't need a control module because they're almost impossible to find now. Read on to learn about my quest.

I needed one on my newly acquired '99 LT with auto temp this past June because instead of fixing what was really wrong (the broken original blend door actuator), the clueless R&R specialists wherever the former owner took it, replaced what was probably a perfectly good control module with a Dorman rebuilt and used the wrong part number!

The GM parts outlets stopped listing new OEM ECC modules for the Blazer a long time ago, and now they all show the rebuilt (Dorman) units as not available anymore either. If you go to the Dorman site, you can't even find the Blazer part number anymore - Only the full sized trucks - and that's the one that was in my Blazer that didn't work. They look and fit the same. But miraculously, after much searching, I finally found a genuine new OEM ECC module at a GM dealer in Puerto Rico! NOS, and only 1 available. And it was priced outrageously at $492!! But I had no choice so I bit my lip and bought it and, thankfully, that fixed it once and for all. So there's always hope but it's a real long shot now.