Author Topic: Air Conditioner wiring  (Read 4104 times)

Raymond

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Air Conditioner wiring
« on: June 04, 2011, 22:54:51 »
I'm attempting to re-install the Air Conditioner and I have two wires that I have managed to lose the labels for.  All of the wires on the uint are black. :(  I have one that I am pretty sure is the power lead that goes to the Red/Green wire on the terminal on the side of the defroster blower.  In the attached photo, it is the one on the right with the terminal connector.  The one on the left goes to the compressor clutch.  The one in the middle is the mystery.  Judging from the cut in the insulation near the end, it appears to have been attached in crimp on tap or splice. 

 I am hoping to avoid having to unwrap the entire wire bundle to trace it out.  Does anyone know to what this wire should be connected?
Ray
'68 280SL 5-spd "California" Coupe

George Des

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Re: Air Conditioner wiring
« Reply #1 on: June 04, 2011, 23:31:35 »
I believe what you got is power, ground and compressor kick-in wires. My guess is the one with blue plastic is either the power or compressor and the one with the ring fitting is gorund. I'd try that set up with a battery power source first before hooking it up to your electrical system to verify it. Hope this helps.

George

Raymond

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Re: Air Conditioner wiring
« Reply #2 on: June 05, 2011, 04:11:53 »
Thanks George.  The blue plastic bullet connector on the left of the photo is the compressor clutch.  That label survived the moving around while I worked on other stuff.  There is a ground from the fan motor.  I thought the wire on the right with the terminal connector was power.  I guess it could be ground? 

I guess I'm down to tracing individual wires.  I found a diagram of the switching in the BBB. 
Ray
'68 280SL 5-spd "California" Coupe

George Des

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Re: Air Conditioner wiring
« Reply #3 on: June 05, 2011, 14:06:42 »
I suspect the ring connector is your ground. Again, an easy way to determine this is to hook up a power source to that and the other bare wire and see what you get.

George

Raymond

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Re: Air Conditioner wiring
« Reply #4 on: June 05, 2011, 20:17:30 »
The ring connector is a ground.  I traced the center wire back to the blower switch.  I found the wire it was originally connected to under the left side of the dash. 

I thought I traced everything from there.  It seemed that the incoming wire is power in to the blower switch.  The blower switch has a power lead to the thermostat.  The thermostat out goes to the condensor clutch and the indicator light.  The indicator light goes to ground.  Does that seem correct?

I am confused about the terminal block that this grounds to.  Photo attached.  There are two wires comiing from the car that appear to be ground.  A brown wire, which I'd expect to be ground, and a Red/White/Green wire that also is grounded.  Where does that Red/White/Green originate?  Why is it a separate ground?  Or is it?

With everything connected as described, it seems to work correctly except that the indicator light is always on even without the ingnition switch and goes off when the compressor clutch engages. 

This proves that even when you think you're adequately documenting disassebly, you should take more photos and write more notes.
 
Ray
'68 280SL 5-spd "California" Coupe

George Des

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Re: Air Conditioner wiring
« Reply #5 on: June 06, 2011, 00:09:43 »
Raymond,

Something is obviously wired in reverse since the blue light should go on when the compressor engages. Try reversing the hot.

George

George Des

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Re: Air Conditioner wiring
« Reply #6 on: June 06, 2011, 00:17:07 »
Raymond,

I just took another look at your last photo. The block where you are tying into looks like the block where your glove compartment light switch should be tying into. On mine, I wired directly to the main fuse box for my power. I know others have wired in a relay to decrease draw across the switches but not sure that is necessary.

George