AC expertise needed please. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jfnar · 05-16-2022, 11:02 AM

The AC on my ’05 silverado isn’t working. The compressor cycles on and off about every 10 – 12 seconds. I hooked up a DIY freon kit and the pressure goes back and forth from about 15 to 70 but it doesn’t seem to be taking any freon. I jumped the low pressure switch and the compressor stays on. I replaced the low pressure switch but no change. Do I need to jump the low pressure switch to keep the compressor running while I try to add freon? Any suggestions will be appreciated.

**hatzie** · 05-19-2022, 07:40 PM

The low pressure cutoff switch will cycle the compressor off when the pressure drops below 20psi.

You'll need to jump the LPCO switch to keep the compressor turning in order to charge the system.

jfnar · 05-20-2022, 08:51 AM

Thanks for the info. I'll probably have time this weekend to try it again.

jfnar · 05-23-2022, 01:12 PM

Just to wrap this up for future reference; I found that the valve on the freon recharge kit was bad. I bought a new kit and everything worked like it's supposed to and one can later my AC is blowing cold again.

05-16-2022, 11:02 AM	#1
jfnar Registered User Join Date: Jul 2009 Location: Jonesboro, AR Posts: 410	AC expertise needed please. The AC on my ’05 silverado isn’t working. The compressor cycles on and off about every 10 – 12 seconds. I hooked up a DIY freon kit and the pressure goes back and forth from about 15 to 70 but it doesn’t seem to be taking any freon. I jumped the low pressure switch and the compressor stays on. I replaced the low pressure switch but no change. Do I need to jump the low pressure switch to keep the compressor running while I try to add freon? Any suggestions will be appreciated.

05-19-2022, 07:40 PM	#2
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: AC expertise needed please. The low pressure cutoff switch will cycle the compressor off when the pressure drops below 20psi. You'll need to jump the LPCO switch to keep the compressor turning in order to charge the system. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

05-20-2022, 08:51 AM	#3
jfnar Registered User Join Date: Jul 2009 Location: Jonesboro, AR Posts: 410	Re: AC expertise needed please. Thanks for the info. I'll probably have time this weekend to try it again.

05-23-2022, 01:12 PM	#4
jfnar Registered User Join Date: Jul 2009 Location: Jonesboro, AR Posts: 410	Re: AC expertise needed please. Just to wrap this up for future reference; I found that the valve on the freon recharge kit was bad. I bought a new kit and everything worked like it's supposed to and one can later my AC is blowing cold again.



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