A/C compressor not turning on

GORDONS610

MEMBER
2006 CHEVROLET EXPRESS
6.0L
V8
2WD
AUTOMATIC
88,113 MILES

I have change the A/C compressor and the accumulator and new belt. It was bought 6 months ago and still having some problems with the A/C the compressor does not turn on. So I check it power and none was going to it. So I then check the relay and no power there. I went to the fuse box under the seat and check the fuses and to see if the 10 amp and 20 amp post where getting power and they are. I have read that since the unit had no Freon in it that the pressure relay is not letting it get power. I cannot add Freon with the compressor not on. So once again I am at a stand still. Help

5 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

Low Freon will not cause no power to the relay.

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

How long did you vacuum the system? It should draw in the first pound right away.

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

I attached a wire diagram for you.

Verify powers to the the relay. You need 3 powers with the key on.

https://www.2carpros.com/articles/replace-blend-door-motor

Roy

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Saturday, July 4th, 2020 AT 1:55 PM

GORDONS610

MEMBER
3 POSTS

I vacuumed it down for 2 hours. Then I checked everything was holding so I figure no leaks. I then went to start the truck and added maybe 10 oz of 134a and stop taking it. I notice my was belt came off. I knew then the compressor never even turned on that is why the gauge read full and it took no more Freon, it should take like 28 oz . When I finally got belt this morning and it stay on I checked the my A/C gauges again. They held. I check all fuses which is 3-10 amp and 1 -20 amp. I check the fuse and the ports. Everyone there works. Now the relay I changed with others that I knew that work, still no power at the compressor wiring. I check the ports at the relay and no power at all there.

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Saturday, July 4th, 2020 AT 4:41 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

Okay, in the last post, I attached the relay diagram.

Did you check for power to both sides of the fuses? If you have power and there is no power to the relay, you need a fuse box.

Can you please verify the voltage to the fuses?

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Roy

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Saturday, July 4th, 2020 AT 5:24 PM

GORDONS610

MEMBER
3 POSTS

Hello there. Yes, I checked the ports you wanted and it is a new fuse box. One of the 1st thing I changed when I got the truck. I also changed the blower, A/C controls and the relay for the blower. Once I change the fuse box then my blower worked. At one time the blower never worked back in December when I 1st got this truck. So that stuff I work on 1st. So on the A/C side I changed about everything you can change I think. Again thanks for your help. I am now thinking there is a wire either broke or burnout. I will start tracing the wires starting with the wire to the compressor that does not work. Unless you have a another item for me to check. Thanks

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Monday, July 6th, 2020 AT 8:42 AM

ASEMASTER6371