Tahoe Hybrid AC schematic ??

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bbOOmm

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I'm trying to troubleshoot my AC system. The AC was working the last time I used it, which was last fall, but over winter, something went sideways from lack of use. Now all I get is the three LED flashes and no AC.

I checked the refrigerant pressure, its good. The temperature is warm so its not a --too cold to operate-- thing. I replaced the AC relay, no effect so I put the old one back in. The AC fuse is good ( continuity across the terminals with the fuse removed), however I'm noticing there is no voltage at the fuse terminals.

So my questions are ...

Does anyone have the electrical schematic of the hybrids AC system?

The AC compressor is powered by the 300V system, is there a high voltage relay somewhere?

Are there high voltage fuses for accessories that use the 300V system?

Which temperature sensor is the sensor for the AC system? ( I think I saw two behind the grill - driver side and passenger side of the radiator frame)

Which "radiator" fan switches on when the AC system is activated ( driver side or passenger side )

Thanks in advance....
 

BG1988

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is the outside showing the correct temp?

it has to be above a certaint temp for it to run

I know on my grandpas car if it showed the incorrect temp it ment we had no A/C (it showed negative -24 outside = no a/c)


both fans should turn on (or very high mode depending on the out door temp)
 
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DaRosa218

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Having the same issue with my 2007 Yukon 2500, I am not getting a reading on the High Pressure switch despite replacing the switch and harness. I just jumped the relay and installed a switch to turn on and off as needed until I figure it out, however I would not recommend it with a Hybrid vehicle. Hope you find a fix soon
 

BG1988

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I'm trying to troubleshoot my AC system. The AC was working the last time I used it, which was last fall, but over winter, something went sideways from lack of use. Now all I get is the three LED flashes and no AC.

I checked the refrigerant pressure, its good. The temperature is warm so its not a --too cold to operate-- thing. I replaced the AC relay, no effect so I put the old one back in. The AC fuse is good ( continuity across the terminals with the fuse removed), however I'm noticing there is no voltage at the fuse terminals.

So my questions are ...

Does anyone have the electrical schematic of the hybrids AC system?

The AC compressor is powered by the 300V system, is there a high voltage relay somewhere?

Are there high voltage fuses for accessories that use the 300V system?

Which temperature sensor is the sensor for the AC system? ( I think I saw two behind the grill - driver side and passenger side of the radiator frame)

Which "radiator" fan switches on when the AC system is activated ( driver side or passenger side )

Thanks in advance....
both fans should turn on

the temperature i'm talking about is the one of the mirror if it shows a -- then it will not work(the A/C)


there should be a high voltage relay it's high voltage after all


more then likely the relay would be inside the battery pack..( you will need high voltage gloves to enter that space)
 

dnt1010

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CAUTION: The system is very similar to the engine driven belt systems except for 1 VERY IMPORTANT difference. The AC compressor is not run from a belt off the engine (mechanically driven) it is as you mentioned an electric compressor running high voltage. The most critical issue is to NOT introduce any std CONDUCTIVE PAG refrigerant Oil or sealer products into this system. The windings on these electric compressors are very sensitive and must have a special NON CONDUCTIVE refrigerant oil. If the windings show any fault to ground the computer will shut the system down. You MUST AVOID using anything other than PURE R134A! If you use a premixed container from your local auto supply it probably will have Conductive PAG oil mixed in it or some sealer products that will completely destroy your Hybrid AC system. HEADS UP PEOPLE this is important. No one owning a 10+ year old vehicle (worth 5k) wishes to spend 10k replacing the entire AC system due to a simple error. There are only a few nuances on these hybrids but if you do not know them you can cost yourself thousands.
 

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