high pressure switch

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high pressure switch

Postby bagadaddy71 » Wed Jul 01, 2009 1:01 pm

I have a 88 chevy k1500 retroed for r134, the serptine belt broke and broke the clutch coil spade off. I have another Harrison R4 but it does not have a hole for high pressure switch, is the switch built in or do I need one with switch hole to install switch in. Replacement compressor came off a 90 full size chevy van
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Re: high pressure switch

Postby Tom Greenleaf » Wed Jul 01, 2009 1:24 pm

It didn't come with a HPCO switch. If one was added for the conversion is should be obvious. There may be a thermal cut out on back of compressor and a blow out device,

T
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Re: high pressure switch

Postby bagadaddy71 » Wed Jul 01, 2009 3:23 pm

Where the switch is on the old unit it is not on the replacement unit, no C clip and cover no nothing. Could it be internal??? :?:
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Re: high pressure switch

Postby Tom Greenleaf » Wed Jul 01, 2009 9:31 pm

If converted there should be a HPCO switch near compressor or high side of course.

Back ups are a pressure blow out switch or a cut of for high temp monted at rear of a compressor help by snap ring typically,

T
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Re: high pressure switch

Postby GM Tech » Thu Jul 02, 2009 2:42 am

The switch in the OEM compressor was a single wire that grounded out with high pressure which throws the recirc door closed-- puts the system into recirc when head pressure goes above 275psi-- so is yours a single wire switch? if so ground it permanently-- there was a TSB to do this on '88 and 89s --I did a bunch of them,......

you could also transfer the coil from the new compressor to the old compressor--I would have just put a new coili on it, instead of buying a whole compressor
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Re: high pressure switch

Postby bagadaddy71 » Mon Jul 06, 2009 8:22 pm

The truck has a single wire but the compressor does not have a place to hook it to. Most R4's have a hole in the back with a C clip and plug or a switch installed. this one has nothing. It has two holes for high and low lines, rest of the housing is solid. It is a Harrison Mod. 3090927
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Re: high pressure switch

Postby bagadaddy71 » Mon Jul 06, 2009 8:24 pm

My go with the coil swap...but bearing bad on old compressor, how hard is it to change bearing??
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Re: high pressure switch

Postby GM Tech » Mon Jul 06, 2009 10:30 pm

Like I said before- ground the single wire permanently and forget the switch- you don't need it.....
'95 Chevy 3500 454 Dually 142,000 miles
'94 Chevy Astro Van 358,000 miles!
'86 Buick Park Ave 192,000 miles
'86 GMC S-15 Pick-up 150,000 miles
'92 Chevy Lumina Van - 265,000 miles- given to me to see how far it can go! all above are white!
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Re: high pressure switch

Postby bagadaddy71 » Tue Jul 07, 2009 4:31 pm

Thanks... I'm such a dumb a$$, found the switch, it'a a screw in type, threaded hole for wire screw was filled with black crud and looked like a solid piece....and to think...I work on TF-34 A-10 jet engines :oops:
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Re: high pressure switch

Postby bagadaddy71 » Tue Jul 07, 2009 4:36 pm

Will ground the wire and go from there
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