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Re: L300 a/c - compressor wires

Posted: Sat May 14, 2016 5:27 pm
by Growlerbearnz
Great!

The +12v wire to the compressor doesn't go straight to earth/engine body, it first goes through a coil behind the pulley. If you look at the compressor with the engine running but AC off you'll see part of the pulley spins, but the steel disc at the front stays still. When you turn on the AC the coil creates a magnetic field which attracts the disc to the pulley, and starts it spinning, running the compressor.
Compressor copy.jpg
Compressor copy.jpg (55.72 KiB) Viewed 3950 times

Re: RE: Re: L300 a/c - compressor wires

Posted: Sat May 21, 2016 7:34 am
by ynwa
Growlerbearnz wrote:Great!

The +12v wire to the compressor doesn't go straight to earth/engine body, it first goes through a coil behind the pulley. If you look at the compressor with the engine running but AC off you'll see part of the pulley spins, but the steel disc at the front stays still. When you turn on the AC the coil creates a magnetic field which attracts the disc to the pulley, and starts it spinning, running the compressor.
Compressor copy.jpg
Interesting side bar, my bus has a wire spliced into tue ground side that ran to a toggle hacked into the side of the shifter housing.

Had no idea what it was until recently. I guess I'll find out when i try to run the ac. :) seems my stock switch may be somewhat buggered if I'm reading into that right.

Good post.

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L300 a/c - compressor wires

Posted: Thu Apr 26, 2018 3:47 pm
by lrp374
I was repairing a broken vacuum relay for the idle bump when the A/C is on after I had some work done on my van over the winter. I found a wire in the same loom that looked like a ground wire so I tested it and now my A/C doesn't work properly. Does anyone no where this wire goes. It seems to be something to do with the A/C. Ypelex's pictures ac1 &2 seem to show it going under the floor? I've looked and I see nothing.

L300 a/c - compressor wires

Posted: Thu May 24, 2018 7:14 pm
by Stella87
lrp374 wrote:I was repairing a broken vacuum relay for the idle bump when the A/C is on after I had some work done on my van over the winter. I found a wire in the same loom that looked like a ground wire so I tested it and now my A/C doesn't work properly. Does anyone no where this wire goes. It seems to be something to do with the A/C. Ypelex's pictures ac1 &2 seem to show it going under the floor? I've looked and I see nothing.
I just made a fresh post about my ac issues, and as far as i understand it, that could be your thermo switch. GrowlerbearNZ said that he bypassed his thermo sensor by the coolant hose and put a loop terminal on it connecting it to the top of the idle up solenoid (if i remember correctly) because the way that switch works is that it sends that wire to ground anyways unless the coolant gets too hot, in which case that sensor takes the wire off ground and turns off the compressor. Have a look through the thread in the technical library and look for the pic with the blue and yellow wire going to the thermo sensor spade terminal. In your picture it looks as though the ran a new wire for the blue and yellow because that wire does not look factory
*edit* also im tired sorry for the jumbled post

L300 a/c - compressor wires

Posted: Tue May 29, 2018 6:49 pm
by lrp374
The wire in question turned out to be the ground for the condenser fans and likely a few other things. I put it back ( and the repaired vacuum solenoid ) and all worked except for the smoke I let out of the A/C Timer relay. I guess some of my testing was not non-destructive. A well placed jumper in place of the circuit board solved that problem on a temporary basis and now it blows nice cold air --48 degrees F.

L300 a/c - compressor wires

Posted: Tue May 29, 2018 8:15 pm
by Growlerbearnz
Damn, I missed this post the first time around! But you figured it out :-)

AC blowing -48F air! That's pretty good AC!