A/C clutch not engaging

JLBMUSIC

MEMBER
2010 FORD FUSION
160,000 MILES

All of a sudden my A/C clutch will not engage. Low side pressure reads about 37-38 PSI. Fuses and relays are good. Clutch engages if I take the relay out and jump it there. High side pressure switch is good. I'm not sure what else could be the issue or what to check next.

Monday, March 29th, 2021 AT 12:33 PM

3 Replies

ASEMASTER6371

MECHANIC
52,796 POSTS

Good afternoon,

What is the high pressure on the system? The fact you have only 35 pounds on the low side tells me you are low in Freon. The low side with the motor off should be close to ambient temperature.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I attached a wiring diagram for you to view. Check the fuse I circled for power with the key on. That powers the relay for the control side. You should have 2 powers at the relay with the key on. Pin 30 and pin 85.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy

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Monday, March 29th, 2021 AT 1:56 PM

JLBMUSIC

MEMBER
2 POSTS

I download the FORScan app and got these readings. See pic.

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Tuesday, March 30th, 2021 AT 8:34 AM

ASEMASTER6371

MECHANIC
52,796 POSTS

Okay, thanks. The fact the pressures are not the same tells me the expansion valve is bad and needs to be replaced. The dryer cartridge needs to be changed as well. It is on the side of the radiator and is accessed from under the car.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Roy

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