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-   Buick (https://www.gmforum.com/buick-172/)
-   -   A/C clutch will not engage (https://www.gmforum.com/buick-172/c-clutch-will-not-engage-313100/)

cliff 03-26-2020 08:22 PM

A/C clutch will not engage
 
1999 Buick Lesabre limited 3.8 engine The A/C clutch will not engage when I turn on the AC, I checked to see if the clutch will spin free and it does, what should be my next step?

Soft Ride 03-26-2020 11:33 PM

Get a new connector or alligator clips and try applying 12V momentarily to the coil & see if spins then.
My issue was with the connector and fried wires.
Post 33 is page 4 with a built in diode, that is required.
https://www.gmforum.com/buick-172/c-...-302417/page4/.

cliff 03-27-2020 10:46 AM

thank you

Mad_Coachman 03-27-2020 02:48 PM

If you are low on Freon the clutch will not engage until there is an adequate amount in the system.

CathedralCub 03-28-2020 12:03 AM

What they said ^^^^^^^

. . . and it could also be the pressure switch.

cliff 03-28-2020 08:43 AM

thank you,in my research that is one of the possibilities as to why the clutch will not engage, along with the pressure switch, another thing that i just now remember I had the car in the repair shop a month ago, I wonder if there might be the reason its not working because they had to but in a new radiator and motor mounts

CathedralCub 03-28-2020 11:05 PM

It could be. They might have accidentally broken something.

cliff 06-04-2020 09:14 AM

its been awhile and had to leave off the ac problem for a bit, I am back I was able to connect a jumper wire to the 30 and 87 terminals into the harness after removing the relay and started the car to see if the ac clutch works and it does, so then i assume what i did was bypass the pcm using the battery as power, which suggests that the wiring is ok, i replaced the relay with a new one, turned on the car and it did not engage the ac clutch, i assume i need to get a set of gauges for the ac system to see if I have any freon in the system, a guy on you tube said that when i hook up the gauges and if the system is charged, without turning on the car I should get a reading on the low side that is close to the temperature outside, for example if it is 80 degrees outside the gauge should read close to 80, I assume that the pcm is not getting the necessary reading to engage the clutch to the ac compressor which also could be a bad pressure flow switch, therefore i assume i might has to replace the switch.

Mike 06-04-2020 12:52 PM

He's partly wrong.

https://cimg0.ibsrv.net/gimg/www.gmf...e2efd905be.png

cliff 06-04-2020 03:46 PM

thank you Mike, I rented some gauges and a vacuum pump from oriellys, when i put the gauges on the low and high side the low reading was 30 and the high was 7, this was without the car running, I let the gauges on for about 45 minutes and both gauges read 0, i sure i have a big leak some where,I put the vacuum pump on for the heck of it just to see what happens,I will let you know in half an hour with the results


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