A/C Compressor problems

[taylorham]

OK I know this has probably been beaten to death but Im at a stand still.

1999 Tahoe.
Compressor stopped kicking on... It was working fine then went out and only came on twice in last month or so.
I have a new compressor, 2 new control head units. 90 degree weather and the charge was 100 psi.
I had a AC shop install compressor and charge it and it worked fine for a few months.
I jumpered both high and low switches. Swapped relays and checked all fuses.

Compressor still will not come on.

any one got any recommendations?
Thanks
Pat

 

[SunlitComet]

Try applying 12 volts directly to the compressor clutch.

---------- Post added at 04:43 PM ---------- Previous post was at 04:42 PM ----------

thru a fused wire directly from the battery of course.

 

[taylorham]

Did as suggested. Compressor clutch kicked on

 

[SunlitComet]

so if the pressure switches are operating correctly and reporting to the pcm correctly then the relay to the clutch or the pcm controlling the relay is defective. a scanner that can read gm data can tell you what it sees from the pressure switches and the outputs and requests for a/c say.

 

[taylorham]

Found it
Connector for compressor had loose wires, all fixed