Intermittent A/C not working properly?

FIXXER25

MEMBER
2012 BUICK REGAL
4 CYL
TURBO
2WD
AUTOMATIC
120,000 MILES

I took it to a tech who vacuumed the system and recharged. The A/C now works fine while driving, however, when idling, both front fans go on and off intermittently, causing the A/C to blow hot every time the fans stop. The fans work in unison, either on or off. When the fans stop, the compressor clutch still continues to turn. I have checked all five relays that support the fans, and they are working. I don’t know what to do next.

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
42,968 POSTS

It sounds like the system is under or over charged, the high side pressure should be about 270 PSI when the outside air temperature is about 90 degrees. This video can help show you:

https://youtu.be/4EqdrBVb0sY

also, this guide can help as well:

https://www.2carpros.com/articles/comprehensive-guide-troubleshooting-intermittent-automotive-air-conditioner-problems

Can I ask if you had this problem before the A/C charge? Please go over these guides and get back to us.

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Thursday, August 3rd, 2023 AT 1:46 PM

FIXXER25

MEMBER
2 POSTS

Hi Ken, yes, the problem existed prior to the recharge. When I picked up the car yesterday, the A/C worked constantly while driving, and the fans (and A/C) would come on intermittently while idling. Now, the fans and A/C do not come on at all while idling. At 75F, the low side pressure is 60psi, and the high side pressure is 90psi, much lower than it should be. The compressor clutch spins constantly when the A/C is on. Appreciate any additional insight.

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Thursday, August 3rd, 2023 AT 3:26 PM

KEN L

MASTER CERTIFIED MECHANIC
42,968 POSTS

Yep, you have a bad compressor, here is a generic guide to help you step by step with instructions in the diagrams below to show you how on your car:

https://www.2carpros.com/articles/replace-air-conditioner-compressor

and

https://youtu.be/4EqdrBVb0sY

Check out the images (below). Please let us know if you need anything else to get the problem fixed.

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