The internals of the switch were not dirty. The problem was loss of continuity between one of the contact blades and the solder post. I re-soldered and now the switch works.

dinner break....

then I’ll put it back in the truck and real time test.

 

Switch back in truck and system works. Im waiting for warmer weather to put it through some real testing

 

Sounds positive !!!

I bought my '88 B2200 in August 1994 with a bad compressor. I replaced the compressor myself, maybe a year later I had an issue with the AC push-in switch. I remember pulling the switch rearward (both wire harnesses still attached) and cleaning it in place, in the truck cab. That's the switch that's still working in my truck.

The other switches I'd fixed and sold I did on the bench. Glove box had to be removed to pull those at the parts yard. Mr. Ohmmeter was needed to confirm repair.

 

Nice 80 degree day here so I finally got around to charging the ac. Started with weak performance of only a 10 degree drop from ambient to 70 degree. After charging I’m getting 40 degrees at the vent in recirculating cab air with windows closed and 50 degrees at vent pulling 80 degree ambient fresh air. I’m satisfied.

 

That's real good, and will be better once the truck is actually moving. Congratulations.

Remember: if the refrigerant does leak out over time: fix the leak, never add any sealant or refrigerant containing sealants !!!

 

Where is the condensate drain on these trucks? I need to get at it and make sure it’s clean.

 

Under the dash on the passenger side. There's a rubber hose that goes through the firewall that drains the water to the outside.

 

got it thanks