Re: 1997 A/C is intermitant...help requested.

Mike Levy · 2003-08-14T15:27:32+00:00

I had a similar problem on my R-12 equipped 94 Jimmy. Replaced thelow pressure switch and it's worked 100% of the time since I replacedit, except when the fuel pump died. Part was around $20 at a dealerand I was able to replace it myself without evacuating the freon.Dunno if yours is the exact same thing, but it would be a cheap placeto start. Here's a good test for the switch, when the system stopsworking pull the plug and short the 2 contacts on the plug, not theswitch, with a piece of wire, if the compressor comes on, the switchis bad. Mine was located in the accumulator, dunno if yours is thesame.

Aug 14, 2003 1 Replies

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I have a 1997 GMC Sierra with 350. I can go out and crank it up and

>the AC will blow ice cold, for a long as I am moving or do not shut
>either the AC or the engine off. If I shut it off an then turn it on
>again the AC will blow warm air and get progressively hotter. It does
>not matter if I only drive 1 mile or 100 miles. I thought it may be
>freezing up, but it was not. I thought it may be a bit low on freon,
>so I bought a recharghe cyclier of freon, but then I noticed when this
>sudden stoppagage of cold air occurs the compresser is not turning. I
>figured its got to be low on freon and the pressure switch is keeping
>it from running. I wait and catch the system when it is working and
>hook up the charge cylinder and gage, but the system shows sufficient
>freon, so that should eliminate low freon as a problem.
>
>When it does work its good and cold. I am at a loss.any ideas what to
>look for? Possibly a clogged dryer? Vehicle only has 50K on it. Taking
>it to a dealer is out of the question for now.
>Regards

I just got finished with playing with this system. I too have come to the conclusion its the pressure switch. I can start up the AC watch the clutch on the compressor kick in, and everything works. Then it will click off, and just a jiggle of the plug on the LP cutoff switch is enough to get it going again. I also used a jumper and it will just keep runnning and running and running. Compressor etc all sound fine, but I did manage to add a small amount of freon, hope tht does not hurt anythng, but its getting super cold now, just like when new. MAybe it was a bit low, but I do honestly thnk its that switch on the accumulator.

Thanks for your input Regards

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foundry and general metal working and lots of related projects.Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove capital A from chipmAkr for correct email address

Re: 1997 A/C is intermitant...help requested.

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