no power to my compressor clutch

stain

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I am re-installing the a/c system in my 1968 New Yorker. I don't have power going to the compressor clutch with a/c turned on. In my wiring diagram it shows a "time delay relay " between the switch and the clutch. Where is this relay? Can it be bypassed?
 
Are you sure you are not low on freon? If so, the binary switch on top of your drier will tell the compressor not to start.
 
No. I just charged it. I can run the compressor by applying 12volts and the a/c blows cold.
I dont have any switches on my drier
 
I guess it could be a broken wire or bad firewall connection somewhere then. With a non standard setup, it could be most anything. Research is inevitable.
 
It is the stock set up. I know power is not present at the firewall. Before I dig into the switch, I want to try to locate the relay and see if there is power there. I don't know where the relay is.....
 
It is the stock set up. I know power is not present at the firewall. Before I dig into the switch, I want to try to locate the relay and see if there is power there. I don't know where the relay is.....
The stock set-up has the binary switch mounted to the top of the drier that the power wire goes thru that monitors the freon pressure. When it detects low pressure, it will not send power to the compressor. The only time delay that I am aware of is mounted to the bottom of the heater box but that has to do with the defrost system.
However, I would suspect your AC vacuum switch could be the problem. They are the usual suspect. This.......

s-l1600.jpg
 
the time delay relay (which doesn't look like a relay at all) is located on the bottom of the a/c heater housing on the passenger side...below the flap that determines whether the blower pulls in outside air from the cowl or recirculates it from inside the cab...it turns the compressor on for a couple minutes in the heat or defrost position to help dehumidify the air...a 68 doesn't have a pressure switch from the factory...i don't know if a bad delay relay would cut power to the compressor during normal a/c operation or not
 
Thanks, found the relay. I need to see if there is power to the switch now.
I have had the ash tray assembly out of this thing about 10 times now. With the center console it is kind of a pain.

You are correct, there isn't a hi/low pressure switch in this system. Maybe there is on auto temp, but this is not an auto temp system.
 
I have yet to get into diagnosing my a/c clutch power situation BUT now the clutch runs all the time! The only way to shut it off is in the "off" position on the heater switch.
I am leaning towards a switch assembly if I cant clean it up.
 
After installing a "new" NOS switch, my compressor won't shut off in any position. After some diag, I found the new switch to be faulty. The "off" position dose not cut power to the compressor. It only works if I press the "off" button, then pull that button back out manually, then the power is cut off to the compressor.
It turns out my original switch was working as far as compressor control, but not air flow control.
I guess I need another switch. I am tired of removing that thing.
 
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