A/C system control

[Renie]

Help please: What is the power source for the Denso AC system controller? I have isolated the fan, AC, condensor and heater... all work if I isolate. The a/c light on the dash does not light up and I do not know how to check if the Denso controller is receiving power

[BFlinn181]

The A/C compressor electric clutch is controlled by a low pressure switch in the coolant lines. If pressure is low, the compressor won't come on. I'm un-aware of electricity in the condenser, did you mean the electric clutch in the compressor?
Usually the bulb or LED that illuminates the control panel gets it's power from the light switch. It is only powered when the parking or head lights are on.

Wiring diagrams for A/C systems are available in Google.

https://www.google.com/search?q=Dens...ih=701#imgrc=_

[chboone]

You can download wiring diagrams and manual here.

HVAC Systems | DENSO Heavy Duty