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So my AC quit. No power at the compressor but works as soon as I short circuit at the accumulator. There is power at the R3 terminal and the R3 relay tests fine. But the clutch does not engage when I short circuit at the R3 terminal. I suppose I need to check the connections at the bottom of the R3 terminal in the engine fuse box.





I have the fuse box loose, but how do I get inside it? The fuse box interior has that outer shell that was bolted to the car. Does that outer shell come off? Or does that R3 terminal pop out? I don't want to force anything around that area.
 

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So my AC quit. No power at the compressor but works as soon as I short circuit at the accumulator. There is power at the R3 terminal and the R3 relay tests fine. But the clutch does not engage when I short circuit at the R3 terminal. I suppose I need to check the connections at the bottom of the R3 terminal in the engine fuse box.

I have the fuse box loose, but how do I get inside it? The fuse box interior has that outer shell that was bolted to the car. Does that outer shell come off? Or does that R3 terminal pop out? I don't want to force anything around that area.
Not a AC pro but have worked on a few. Since it works when you jump the plug at the accumulator, check your pressure levels. Sounds like you may have lost your charge or there is a problem at that low pressure switch.
 

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Discussion Starter #3
Thanks for responding. Yes, I checked the pressure first. I also changed out the pressure switch just to be safe (it was really old) but there was no change afterwards.
 

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If your pressures are good, you'll have to walk through the circuit to determine what's holding your AC out, What's the year of the car?
 

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The accumulator might be the high pressure switch. You'll need to walk the system with a multi-meter to determine which item is holding out the compressor.

AC_Pg-1.jpg

AC_Pg-2.jpg

AC_Pg-3.jpg
 

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Discussion Starter #7
Wow, thanks. It will take me a bit to decipher the electrical schematics but I'm glad I know what to do next.
 

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Discussion Starter #8
Turned out to be a bad compressor coil. It would engage if I pushed on it with a breaker bar. But it held only for a moment.
 

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Late but may not be anything wrong with the coil at all. If wear allows the airgap there to get too wide then the clutch will quit due to too much clearance there, not enough magnetism to pull the plate over due to too loose. Simply respacing the airgap back to correct can get one back running often for the price of a ten cent washer if needed. Usually though you are removing them and even cheaper. Need like a .030" gap there, no more.
 
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