Hvac systems
 

03 tahoe z71 .
I have checked everything threw out my whole ac system have found out im not getting power to my ac clutch relay whats my next step ? Where are the wires that run to it ?

the ac relay is turned on by the pcm….the pcm provides grd on relay pin 85. this closes the relay to engage the compressor clutch. if you jumper grd to the wire or pin on 85 and the compressor clutch engages...the pcm is inhibiting ac operation

there is a low pressure switch that is an input to the pcm...if the switch is open. the pcm won't turn on the relay. have you checked the switch, is the system charged with refrigerant?

I'm assuming that the system is not really in the trash !!!


OK, like posted previously: get a real set of R134a service gauges and read the static pressure - if any - of your system. Could be that the systems are simply doing their job of protecting the system.

Do NOT "add refrigerant" blindly, and NEVER add any sealers or refrigerant containing sealers !!!

Replying
 

Where is the low pressure switch located? And yes its charged

on the low side....usually around the ac accumulator (the soda can looking thing)