Caterpillar 315c l a/c problem

[truecountry]

Guys I been working on this excavator for a week on a/c unit ..Serial # is Cjc01986
Compressor was locked up replaced it and dryer and expansion valve ...
Pulled a vacuum and a leak on hose ..from expansion valve to dryer
Long story short compressor will not kick on unless I frame ground the blk 14 common wire to compressor
Look at wiring diagram and trouble shooting their is a thermostatic switch that if stuck open will not let compressor kick on ..
My question is where is this switch located at ? it shows a 20 amp and 15 amp fuse with it on wiring diagram but no part number listed
Thanks Allen

 

[Bls repair]

Is there a high pressure and low pressure switch in the drawing?

 

[Theweldor]

A serial # would be most helpful to you and us!!!!!

 

[Cmark]

What wiring diagram do you have? This is what it should be to the compressor. 200-black is always battery negative.

 

[John C.]

I have a code list for the AC units I think that are installed on that model. I'll have to do some digging to find the buttons to push on the AC control panel in the cab to bring up any fault codes. It might take me a bit so if anyone else has the right combination of buttons, feel free to post.

 

[Mobiltech]

If you’re looking for the low temp cut off switch it will be in the evap core in the heater ac unit. It uses a capillary tube in the core to keep it from freezing.