A/C compressor not turning on

2006 CHEVROLET EXPRESS
88,113 MILES • 6.0L • V8 • 2WD • AUTOMATIC
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GORDONS610
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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
Jul 4, 2020 at 11:05 AM
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ASEMASTER6371
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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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Jul 4, 2020 at 1:55 PM
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GORDONS610
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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.
Jul 4, 2020 at 4:41 PM
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ASEMASTER6371
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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
Jul 4, 2020 at 5:24 PM
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GORDONS610
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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
Jul 6, 2020 at 8:42 AM
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ASEMASTER6371
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Okay, again, do you have power to 2 terminals in the relay plug at the fuse block?

Roy
Jul 6, 2020 at 8:45 AM