Finally got to do some more testing on the Tahoe A/C system.
(My daughter-in-law drives it and between work, school and three teenage granddaughters, it spends most of its time on the road. )
Was able to verify clutch operation and wiring to the underhood relay.
Triggering the relay with a lead connected to 12-v brings the compressor on line and the system starts cooling.
Still cannot get a signal on the control line from the interior.
(This with the pressure switch bypassed. - Btw, I checked the pressure switch with a meter and it tests good.)
Looks like I still need a diagram of the control circuitry in the dash.
This Tahoe does not have the 'Climate Control' version, it is the manual control system.
Thursday, July 28th, 2011 AT 3:50 PM