A/C not working

2003 CHEVROLET SUBURBAN

200,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC

JOIHN CONOLY

MEMBER
2 POSTS

Plug in control panel and blower kicks on high fresh air, button light, A/C button lit and back window defrost light lit, but can't control anything nor get A/C compressor to kick on. got instrument cluster working was a blown radio fuse that was weird.

Jul 4, 2021 at 3:13 PM

ASEMASTER6371

✓Experienced Mechanic
52,796 POSTS

Good morning,

If the compressor does not engage, the first thing you need to check is the Freon pressures. You need at least 20 pounds on the low side for the compressor to engage.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Check the high and low side pressure with gauges. You can rent them at a parts store.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I also attached the diagram for the compressor. The relay will engage when the ECM sees the correct signal from the high-pressure switch on the compressor and the low-pressure switch on the dryer. I attached the locations for you as well.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Roy

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