# A/C Clutch Amperage?

Discussion in 'The Garage' started by 73k5blazer, Jan 3, 2007.

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Does anybody have any reliable info on how many amps the old long style GM AC Clutch uses?
I'm wiring, and searching around I see various things rangin from 2.5amps to 18 amps . I'm using it for an onboard air system.
I suppose I could go get a cheap inline fuse holder and a bunch of fuses of different amperages and watch them burn up, but, I figured somebody might know?

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3 amps for the clutch on the longer round compressor. (tested mine)

Last edited: Jan 3, 2007

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Alright! That matches my calculations.
Well, I dusted off the old brain cells I built up in college, and using ohms law, I measured the resistance of the clutch, at 4.1ohms, using the formula
amps=volts/ohms
14/4.1=3.4amps
Not a perfect number, but a good overall idea of what it could be. Add a couple for saftey.

I guess the 12ga wire I used is overkill

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I measured the draw with a meter so your calculations and my measurements, should be pretty darn close.

How are you oiling this compressor???

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I've an oiler on the inlet side and a de-oiler on the outlet side.
The de-oiler drain will be plumbed to the oiler fill, so it'll be somewhat automatic.
I've an old writeup from a mid 90's Fourwheeler mag on how capable these compressors are, only downfall, they aren't internally lubricated, but the oilder/deoiler should take care of that.
They ran without any lube for many months and didn't report any problems.

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If it is an A6, then it is most certainly internally lubricated. The bulge in the bottom is an oil sump, and it has a gerotor oil pump located in the rear housing. Still, the oiler/deoiler is needed because it does tend to discharge a bit of oil along with air (or refrigerant in it's normal use). Not much, but a little bit.

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Hmm...so I've one from my '73 K5, long style, and it has a bulge on it, and I've one, long style, from an early 80's GM car, long style, but no buldge.

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The heavy-@\$\$ one with the bulge is an A6. The other one is probably an HR6. A6's are readily identifiable by the bulge and the cast iron end plates each attached with 4 nuts. That and they weigh a ton

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Hmm, well, thanks! That's good to know. I was tempted to use the newer one, because, it's newer, I didn't know there was a difference, but now I do!
I'll have to see if the clutches swap though, because the clutch on the 73 one is completely shot, the newer one works though. Those clutches are \$100!