What "exactly" is it called?

[N2TRUX]

I know I should know the answer, but it seems I do not. While cleaning my motor I decided to replace a couple of sheet metal screws because my rag kept getting snagged on them. The screws were holding this "item" in place and in the process I broke the hard line off.

I have searched Google to death and can't come up with the correct name. I "think" it's called an a/c cycle but that doesn't come up. My buddy suggested High Pressure Cycling Switch (aka High Pressure Switch) but that comes up as the pressure switch in all my searching.


What "exactly" is it called, and where can I buy one?

[BLE 'BURBAN]

Whats the year and model it's off of? I've got access to the GM electronic parts catalog I use at work right here at home now. So get me all the info uou can and I'll check it out for ya. Dave

[f.monroe]

Search Thermostat. That is the older style before they went to the low pressure cycling switch that is mounted in roughly the same place . That hard line penetrates the evaporator and relays the temp to the switch for cycling purposes .

At least that is what I think I am looking at and if it is , it would be mounted using two small sheet meatl style screws .

Looking at the pic it looks like your system has been converted to a low pressure switch already . It looks like one is mounted right by your low side port .
Frank

[powerdriver 1958]

out of a chiltons

[N2TRUX]

Dave- It's on my 77 Cheyenne.

Frank- I'll get a better pic, but that description of how it's mounted is correct.

PD- Thanks for the diagram.

[Pyrotechnic]

My 77 has the same thing. It also had a switch on the evaporator inlet that I was told was a high pressure cut off. When I had the lines custom made while I was converting to R134A, the guy gave me a retrofit low pressure switch that screwed onto a port on the accumulator. I simply took the plug for the high pressure switch and extended the wires to the new low pressure switch.

Both are wired up. I'm guessing the thermostat isn't necessary now ? Works fine as it is now.

[f.monroe]

Ken , I am pretty sure that is the thermo you have pictured and that I am wrong on my assumption that yours is converted . I looked at the pic again and the switch I see is on the high side , just before the expansion valve . It becomes low pressure just after the switch I see in the pics . Since yours is broken , I would look at converting to a LP cycling switch . Just a couple wires and a screw on switch that would attach at the port I see on the top of your accumulator .
Frank

[N2TRUX]

Thanks for the follow up Frank. Since the truck was sitting for so long, the a/c seems to have lost some freon. It wasn't blowing as cold as it did when we first swapped the motor. I plan to take it to a local shop and have them check it out. I will assume he can do the conversion.

Here are some more pics. Not much better quality though.