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Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Car
Satisfied Customers: 47346
Experience:  16 years of experience
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buick reatta: a/c compressor will not come on it is new and

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a/c compressor will not come on it is new and have new dryer bottle installed when it was put in a/c worked and then got home turned off the car and when i started it again the a/c did not work ,have taken battery cable off and it seems sometime will rest and work for a bit is there a relay that could be bad stopping the compressor not to get signal to start
terry griffith
it is a 1990 buick reatta

Hello, I'm Chris. Thanks for visiting Just Answer.


Sorry for the long wait.

Many techs have looked at your post and have not felt comfortable helping. This area of concern is not my strongest point but I will try to help as best I can at least with some information. I have access to a lot of repair guides so I should be able to at least do something to aid you if your still needing help and willing to let me try.

Once I post an answer you will be prompted to rate me, not the site or wait time, or the news in my answer. Please let me know exactly what you need from me so I can earn a good rating.



Customer: replied 4 years ago.

so what is your reply on a/c 1990 buick reatta

terry griffith


See the diagram below.


A few things can be wrong:

Faulty relay

Faulty AC clutch

Faulty pressure switch

Bad signals to the relay

Low Freon


You need to check the compressor clutch plug while its commanded on to see if its getting power and ground, if its is but not running then the compressor clutch is weak or has an excessive air gap. If your missing power then check the relay pins 4 and 2 should be power from the fuse and pressure switch and BCM. Pin 5 needs to be ground from the ECM.

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