A/C does not work, there are five volts at the low-pressure switch?

2003 CHEVROLET SILVERADO

140,000 MILES • 6.0L • V8 • 4WD • AUTOMATIC

BRACKETT

MEMBER
1 POST

A/C System is fully charged. I have five volts at the blue wire for the low-pressure switch and a good ground. When plugged in I have ground on both sides. High Pressure switch five volts on gray ground on black and .4 on red when plugged in. A/C request says Granted. fuses and relays are good. I jump the relay and the compressor clicks on. I have both powers at relay on and ground from compressor side but no ground from PCM.

Oct 15, 2022 at 1:36 PM

STRAILER

✓Experienced Mechanic
55,267 POSTS

You should have 12 volts at the low-pressure switch. It sounds like you have a bad climate controller. Here is how to change it out, also you can check for 12 volts at the fuses here is a guide to help you check and the A/C wiring diagrams so you can see how the A/C system works. Check out the images (below). Please let us know what you find. We are interested to see what it is.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
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Oct 16, 2022 at 5:07 AM