Thanks Ben, just got the confirmation.

I've passed the idea on to Joe for consideration. Until someone confirms a jumper design that works I'm just going to wire a small switch into the purge valve and operate it manually. I'll let someone else play Guinea Pig this time

 

Well, my A/C is operating normally. I got the new chip in today (oddly enough it was a LM2902N instead of the LM324N in the board). I did my first ever PCB circuitry, I was so scared of damaging the board it took me an hour and a half roll of solder braid to get the old chip out. But I just fired up the car and the compressor comes on and off with the dash button as it should.

There isn't much freon or oil in the system so the air wasn't much colder than ambient but any mechanical damage will be much easier to diagnose.

Thanks for all the help guys. Hope this thread can serve as a warning to anyone in the future.

Also Hornet, let me know how your jumper+diode works. I don't want to abandon this idea completely. For the time being I'm just going to wire the purge's ground to a switch in the cabin but I would like a more automated system if you figure it out.

 

Planning to try it this coming weekend.