R12 Charging Problem

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robmaxfli
Posts: 22
Joined: Fri May 13, 2016 7:07 am

R12 Charging Problem

Postby robmaxfli » Fri Aug 11, 2017 5:42 pm

Been working on the 1992 Buick r12 AC for over 2 months now - I have studied the charging procedure over and over - every single piece of hardware is new - held great vacuum . Did all my pre-checks....Today was the big day to finally charge and then ...flop..

With the car off, I charged one 12oz. R12 can as a liquid on the High side (HR6 Compressor). no problem there. Turned off the high side valve and then connected 2nd can to the Low. Turned the car on - Compressor started cycling. It seems that as soon as I open the Low side valve for the 2nd R12 can to flow in , its stops cycling and then both pressures slowly climb/equalize at 110psi - its about a 100deg. here in Dallas. ..Even though I put the can in hot water - upright- seems like no more gas is flowing , compressor is doing nothing and gauges are equalized at 110...I tried to jump the Low Pressure Cutoff switch just to see if the clutch would engage - but nothing happened.

hope someone can assist..thanks
Dougflas
Posts: 186
Joined: Mon Apr 18, 2016 6:10 pm

Re: R12 Charging Problem

Postby Dougflas » Sat Aug 12, 2017 6:34 am

By any chance is your lo0w side hose fitting not opening the low side shrader?
robmaxfli
Posts: 22
Joined: Fri May 13, 2016 7:07 am

Re: R12 Charging Problem

Postby robmaxfli » Sat Aug 12, 2017 9:19 am

Yes.... :twisted:

thank you
GM Tech
Posts: 144
Joined: Fri Apr 22, 2016 7:22 am

Re: R12 Charging Problem

Postby GM Tech » Tue Aug 15, 2017 7:39 pm

You don't "jump" the switch, you jump the connector to the switch....If a/c compressor does not come on when doing this, then you have another issue- such as a relay, or high pressure switch unplugged, or a power steering switch unplugged- get a wiring diagram of your a/c circuit and do the diagnosis of it.

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