LarryL

84 ta, I did a complete revamping of my A/C system. Everything new. Only thing I reused is the high pressure steel line that bolts to the frame. I switch to serpentine belt setup with compressor on RH side. I moved the wires to the RH side for the compressor and used adapter setup that plugs my old compressor plug into the new one.
My problem is on the old compressor hookup there is a wire on old connector (looks like the kind the snaps on to temp sensor in the head). The compressor will not run unless I ground this. When I do, the compressor runs but does not cycle on and off, it stays on all the time. How do I get around this problem. Thanks

Reid Fleming

iTrader: (2)

The system cycles on and off based on the low pressure switch (attached to the accumulator).

In Florida in June, I wouldn't expect it to cycle off unless you're driving at night on MAX A/C and slowest fan speed.

l_dis_travlr

If you unwrap the ac-compressor harness, you'll find it has two wires
(green-switched power, & black-ground) series'd into two connectors.
One connects to a minimum charge pressure sensor on the back of the
compressor, the other to the clutch drive in the front. Built into the
harness is a diode, to suppress transient spikes as the clutch cycles
on/off. Reid is correct that the cycling function is driven by a pressure
sensor at the accumulator.

LarryL

Yes, I know the pressure(that is the low pressure) switch controls the cycle. The pressure switch(low) is new. My problem is the compressor will not run if I don't ground the wire that has that connector. If I unplug the (low)pressure switch and ground that wire on the compressor it will stay running with this wire grounded. If stays running the pressures go way too high.
I think you hit the problem on the head. I switch from a DA-6 compressor to a R-4. The DA-6 has a high pressure switch on the compressor for the connector I have been grounding. The R4's pressure switch is different so it is not connected i.e. compressor keeps running when I ground the connector. Now the big question is there a connector adapter or will the DA-6 high pressure switch fit in a R4 compressor. ???????

LarryL

OK fixed the problem.
I had to replace the high pressure switch on the R4 compressor.
I used a Murray interruptor commutateur #35951 in place of the high pressure switch in compressor.

Remove the old pressure switch install new one. It has 2 wire connector. Connect 1 wire to old wire (cut off old connector) other wire goes to ground.

Now compressor cycles as it should. My pressures are down to 35 low and 275 high. Nice cold air.

rfoster23g

great thread

abcx09t

I know this is an old thread, however, i need the connector to the low pressure switch with some wire to replace the one in my 87 IROC. I put the request for the part on the Parts Wanted with no reply...anybody have one to sell?
Thanks,
Scott