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A/C cycling

Clint Bazemore

Active Member
Nov 26, 2017
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Mebane, NC
Need help please. My A/C compressor cycles when the switch is turned off. Works correctly with A/C is turned on. Any help with this issue would be very helpful. Thanks, Clint.
What year Ram? Is it in defrost mode? When you say cycles, do you mean short cycling like it's low?
It cycles when the system is off or any other button is pushed. Works as it should on ac or max ac. Relay at the left hood hinge is getting a signal from somewhere.
1988 w150 318 automatic. Everything is factory on the truck.
That's what I was thinking myself. I can't figure out what is sending a ground signal to that relay by the left hood hinge. I have even put a new climate control switch in the dash.
Try unplugging your 2 prong low pressure switch under the hood on the A/C line and see if it still cycles
I have done that. If the AC is on it works properly. If I unplug that pressure switch with the AC on it starts to cycle. I don't know what I am overlooking.
When the AC is on it works correctly. Site glass is clear with the system turned on. What I really don't understand is it cycles when I turn it off.
Is this something you have had for awhile? Reason for asking is the mentioning of climate control. True climate control systems function differently of normal systems in that some don't really shut down.
Not sure a cheap Chilton type manual even gets into this.
Aldata doesn't cover it very well either. Why would it need to cycle the system when turned off? Going to rebuild the system after I swap in the 360. Might find something then. My 87 didn't do this.
I will have to look through the pile of factory manuals and see if I can find anything close.
When you say cycle, is it off then on multiple times quickly or just once? I am trying to figure out your definition of cycle
I am having difficulties finding anything in the pickup line with climate control.
Std. air should have nothing to the compressor if not in a/c or defrost mode.
Could be a broken control board in the switch it's self is the cause of the problem. But will keep looking. I have an auto manual or two left to go.