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high pressure cutout switch on compressor

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Old 07-08-2019, 04:19 PM
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high pressure cutout switch on compressor

hey guys, i’m stuck. new compressor has hole for one, but i’m not finding a part number for this switch/ sensor, what ever it is. also, the switch wiring is not covered in the service manual. only one in service manual is the one mounted on accumulator

what gives? no part number, not in manual?

the connect is mentioned, but does not indicate where wiring should go as if it does not really exist. yet there is one on my old compressor. don’t really want to leave a connector hanging and don’t really want to use old sensor


Old 07-08-2019, 04:52 PM
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Re: high pressure cutout switch on compressor

Usually, there's a snap ring. Remove the snap ring, pull the switch, remove the plug from the compressor, install the switch, replace the snap ring.
Old 07-08-2019, 05:03 PM
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Re: high pressure cutout switch on compressor

thanks, i see that, but i don’t see replacement sensors available?
Old 07-08-2019, 05:14 PM
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Re: high pressure cutout switch on compressor

Originally Posted by LiquidBlue
thanks, i see that, but i don’t see replacement sensors available?
At rock auto , don't look in the specific air conditioning subsection , look at the "Electrical , switch and relay" subsection at the four seasons compressor mounted high pressure switch , part number 35974 , and see if that will work for you .

PS , interesting change , my 1989 has the high pressure switch in the metal line leading from the condenser to the evaporator .
Old 07-08-2019, 05:19 PM
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Re: high pressure cutout switch on compressor

ah! under refrigerant pressure switch. thanks for the help!
Old 07-08-2019, 05:25 PM
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Re: high pressure cutout switch on compressor

Originally Posted by LiquidBlue
ah! under refrigerant pressure switch. thanks for the help!
Your Welcome
Old 07-09-2019, 06:58 AM
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Re: high pressure cutout switch on compressor

Originally Posted by OrangeBird
At rock auto , don't look in the specific air conditioning subsection , look at the "Electrical , switch and relay" subsection at the four seasons compressor mounted high pressure switch , part number 35974 , and see if that will work for you .

PS , interesting change , my 1989 has the high pressure switch in the metal line leading from the condenser to the evaporator .
No change... You have a high pressure switch in the metal line from condenser to evap, the low pressure switch in the dryer and the cutoff switch in the compressor head. The cutoff switch is just a safety feature to save the compressor in case of extremely high pressure buildup.
Old 07-09-2019, 07:19 AM
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Re: high pressure cutout switch on compressor

Originally Posted by OrangeBird
At rock auto , don't look in the specific air conditioning subsection , look at the "Electrical , switch and relay" subsection at the four seasons compressor mounted high pressure switch , part number 35974 , and see if that will work for you .

PS , interesting change , my 1989 has the high pressure switch in the metal line leading from the condenser to the evaporator .
Originally Posted by J.C. Denton
No change... You have a high pressure switch in the metal line from condenser to evap, the low pressure switch in the dryer and the cutoff switch in the compressor head. The cutoff switch is just a safety feature to save the compressor in case of extremely high pressure buildup.
Yes J.C. , it most certainly is a change ! For the manufacturer to relocate the high pressure cutout switch from the liquid line to the back of the compressor constitutes a change in both the compressor AND the liquid line , parts buying wise , which is exactly what Liquid Blue and I were discussing . No change in circuit function , but BIG change when ordering parts .
Old 07-09-2019, 09:02 AM
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Re: high pressure cutout switch on compressor

Denton is describing what I have in my setup - 1990. If you look at my compressor, it has 1989 stamped on it. The configurations vary over the years. Thanks for help last night, I was stuck in my garage where wifi is on/off and makes it hard to browse quickly for stuff.
Old 07-09-2019, 09:09 AM
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Re: high pressure cutout switch on compressor

Originally Posted by OrangeBird
Yes J.C. , it most certainly is a change ! For the manufacturer to relocate the high pressure cutout switch from the liquid line to the back of the compressor constitutes a change in both the compressor AND the liquid line , parts buying wise , which is exactly what Liquid Blue and I were discussing . No change in circuit function , but BIG change when ordering parts .
I'm wondering from what I found in 1990 Service manual and what you are saying is that this high pressure cutoff switch was added in 1990?? The 1990 service manual glosses over it, indicates it is there, but provides no wiring that I could find. I did notice that when I ran an electrical check that it had some connectivity to the liquid line switch, there was about 2K of resistance between them. They seemed to be on the same circuit, or at least related to the same circuit.
Old 07-09-2019, 09:16 AM
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Re: high pressure cutout switch on compressor

Think I just ran across the wiring diagram. Didn't see this last night. These are the worst wiring diagrams ever! Where is connector 105 in this??? It should be included in this diagram, instead, you have to either have 4 books spread out to different pages or turn pages back and forth. I find myself putting bolts as book marks when micky mousing around with these wiring diagrams.

Attached Thumbnails high pressure cutout switch on compressor-92-7730v8tpi-2.jpg   high pressure cutout switch on compressor-92-7730v8tpi-2.jpg   high pressure cutout switch on compressor-92-7730v8tpi-2.jpg   high pressure cutout switch on compressor-92-7730v8tpi-2.jpg  

Last edited by LiquidBlue; 07-09-2019 at 09:20 AM.
Old 07-09-2019, 04:59 PM
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Re: high pressure cutout switch on compressor

Without digging out the book and looking at a diagram, I want to say it's a redundant switch in addition to the one on the pressure line.

Nothing wrong with those diagrams. They're intended to show the entire system, if you want all the connectors, splices, etc shown you need to look in the wiring diagrams instead of the troubleshooting diagrams. It's all about learning how to use the book.

The worst diagrams ever are the early line diagrams printed on a tri or quad-fold inserts at the back of the books. GM diagrams got vastly better in the mid 80s.
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