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Discussion Starter #1
The A/c System on V8 G8s is prob the most misunderstood system on entire vehicle,no magnetic clutch,no relays.always spinning, but if you have a non noisy comp.and pressure values do not change when comp is commanded on, make sure you have a commanded 4 -14 volts at 2 wire connector at actuator, if present a simple actuator fixes this on most,just unbolt 3 comp bolts and pipe twist comp without removing to access actuator, remove snap ring at actuator and spend another hour working out of comp body ! Reinsert new sol into comp with connector facing rear of comp, install snap ring, reinstall comp, vacuum and recharge system and bam, works as new
 

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Discussion Starter #3
Your saying both wires at the compressor actuator should have 12 v ?
No Sir, between the 2 of them, the dark blue wire is a ground and the green wire is a pulse width voltage from the hvac module.not to confuse the 3 wire sensor in the pipe,it is the 2 wire actuator connector above rear of comp.Also before getting to this point, make sure the 7mm bolt in middle of front comp pulley is spinning with pulley,simply release comp belt and with 7mm socket turn front middle pulley bolt, if it is tight or seized, look no further as comp is gone,when internal seizure happens the lock pin from belt pulley to middle comp shaft de couples so only pulley will spin and not center shaft of actual comp shaft, i will do a full article on this soon with comp internal pics
 

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Compressor is good bolt not sheared like I said , I can get compressor to pump if I Substitute ground wire straight into blue wire compressor usually comes on and blows cold air but lately I have to run the engine at a higher RPM to get it to work
 

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Discussion Starter #5
you will have to get a scanner that reads body codes,like a tech2, and go into Body > HVAC and ck the codes stored there,low press/sensor codes shut the system down to compressor, also there you will see if compressor says granted for operation
 

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Just borrowed a friends scanner that is able to get into the Hvac system. No codes present. Ann’s I can see all the pressures. They all say ok. Also the air is commanded on .

just eliminated the cars havoc system and wired compressor strait to battery and a good ground. The compressor still would not come on so I put the a/c gauges on and pressure was 90 / 150. Tried to service compressor and it would still not compress . Reved engine to 4,500 rpm and then it started to take Freon. 🤔🤔 numbers are now 40/200. Ice cold in cabin of car. So I’m thinking I have to problems. A Freon leak and valve sticking.Still do notknow why I’m not getting a ground at blue wire ?
 

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Discussion Starter #7
At this point you can just run a straight ground to the blue wire and see what it does, either the wobble plate or actuator solenoid is sticking or the ground comes and goes,bypassing the ground/blue wire will eliminate any doubt if it fixes it
 

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I have actually done that already. A good ground going to blue wire . I can here the valve click and the compressor sometime begins to generate cold air . I’m thinking the variable valve or maybe both valve and compressor are bad.
 

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Discussion Starter #9
a replacement compressor comes with the valve,early in the summer i did one for another G8. they bought a brand new one from Pit Stop for 266.00, it looked and worked perfectly new, make sure to replace the receiver dehydrator inside Rt end of condensor.it will be packed with crud
 

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checked blue wire with green wire at compressor and I do have 12 v. So I’m going to buy a new compressor. That should take care if my issues.
 

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Discussion Starter #12
try this one, prob the cheapest but beautiful piece....https://www.pitstopauto.com/Catalog.SKU:CO 29176C
 

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Replaced compressor with new. And I’m back to the same issue. It will not cool unless I run a ground to blue wire. Going to replace the Hvac/ radio unit with the G8 design unit
 
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