Thermostatic switch A/C
 

I have a 77 3/4 4x4 with A/C the PO appears to have replaced the evaporator core, I am going through the system to clean and get working properly. My truck has the thermostatic switch that attaches to the inlet line on the evap. I read the GM service manual and it says to mark EXACT location before removal I am sure the OP didn't do that. What I need is that EXACT location to reattach the capillary tube. If anybody has specific info it would be greatly appreciated.

Re: Thermostatic switch A/C
 

No A/C gurus out there?

Re: Thermostatic switch A/C
 

I do a/c work. Replaced 2 expansion valves last week. The location is NOT critical despite what you might have read.

Re: Thermostatic switch A/C
 

I am certified in mobile A/C but I don't get to practice at it everyday, I have never had to mess with a thermostatic switch before. I have replaced expansion valves though, the capillary usually goes in the evaporator body to get correct readings. I did however read in my newly downloaded service manual (thanks Hatzie) it says to mark location and replace in exact location within 1/2inch either way. just wanted to make sure I get everything out of my A/C.

Re: Thermostatic switch A/C
 

Off the cuff guess but could be so the temp response is similar to the original tube. Different areas of the evap coil are probably different temps due to differences in freon and air flow.

When I replaced the dead one in my 75, I used a pull from a yard vehicle. Had to do a fair bit of adjustment on the switch until it quit shutting off the compressor too early. Don't remember what the source vehicle was. The switch looked the same so figured it would work. Think it cost $3. Must have found a good one since it was over 10 years ago and it still works fine.