A/C Clutch Pressure Switch - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**LEEVON** · 05-18-2013, 05:16 PM

It got freaking hot today...wasn't prepared for that. Ambient outside temp here was about 88 degrees and I've gotten really soft apparently. So I swung by the parts store and got some R134a.

I don't know the history of the a/c system in my truck, just that it's all intact and the compressor was unplugged. I figured I'd take a chance, and I realize this isn't the best way to get a reliable working system. It may take a flush and new components in the future. I also have some R12 stashed just in case. So I plugged in the compressor, started the charge and the clutch wouldn't cycle. I jumped the compressor switch, it cycled and low and behold worked (for now). I could not get the clutch to cycle on it's own with the switch plugged in so I assumed the low pressure switch was bad and bought a new one.

Can I change the switch while the system is charged?

Thanks!

Troy 82 · 05-18-2013, 05:55 PM

yes. Just unscrew & screw the new one on.

Restrorob · 05-18-2013, 05:57 PM

You shouldn't have any issue, There's a schrader valve under it to hold refrigerant in. Just screw the old one off quickly and screw the new on quickly.....

05-18-2013, 05:16 PM	#1
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,893	A/C Clutch Pressure Switch It got freaking hot today...wasn't prepared for that. Ambient outside temp here was about 88 degrees and I've gotten really soft apparently. So I swung by the parts store and got some R134a. I don't know the history of the a/c system in my truck, just that it's all intact and the compressor was unplugged. I figured I'd take a chance, and I realize this isn't the best way to get a reliable working system. It may take a flush and new components in the future. I also have some R12 stashed just in case. So I plugged in the compressor, started the charge and the clutch wouldn't cycle. I jumped the compressor switch, it cycled and low and behold worked (for now). I could not get the clutch to cycle on it's own with the switch plugged in so I assumed the low pressure switch was bad and bought a new one. Can I change the switch while the system is charged? Thanks! Attached Images __________________ '86 GMC C30 Crew ~ '86 C20 Crew ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '74K10 ~ '71 Cheyenne swb ~'50 3100 bagged ~ '80 Wife ~ Late model kids Last edited by LEEVON; 05-18-2013 at 05:28 PM.

05-18-2013, 05:55 PM	#2
Troy 82 Registered User Join Date: Jan 2003 Location: Texas Posts: 75	Re: A/C Clutch Pressure Switch yes. Just unscrew & screw the new one on. __________________ Troy 1982 Silverado

05-18-2013, 05:57 PM	#3
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: A/C Clutch Pressure Switch You shouldn't have any issue, There's a schrader valve under it to hold refrigerant in. Just screw the old one off quickly and screw the new on quickly..... __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*



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