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84 AC High Pressure Cut Out Switch (Compressor Mounted)
I found a number of older threads on the forum discussing this switch but I have been unable to find a replacement switch that threads onto the schrader valve on the back of the compressor. I ordered one that looked correct and stated compressor mounted but the threads were too large. When I got the car the switch was missing and a homemade jumper wire was in place. Hopefully someone here has a P/N and source to purchase.
Thanks
I don't have any info on it. Dad leaned on mine 13 years ago when I was swapping the alternator and snapped it off flush with the base. Techs could never get the AC to hold a charge more than a day before that anyway so said pooey on it. Maybe someday I'll completely replace the entire system.
Anything on CorvetteCentral or rock auto?
I haven't even looked at AC stuff for a decade
I’ve tried all of the parts houses including Rock Auto and none of them list the switch. I did find the original P/N which is GM 10007057 A/C Compressor Switch. I found the part at NAPA but the threaded section that goes on the schrader valve looks too large like the previous one I purchased. I’m going to run over to our local Napa dealer and see if they have one I can look at. An original one is on fleabay is over $100 and no guarantee it is a good working part. I know I could use the system without it but it’s there to protect the system from high pressure that could damage the system according to the FSM. I’m EPA certified Technician Type I, II and III and have been working on A/C systems for over 30 years FWTW…
I see GM 2724279 high pressure cutout fan switch 84-96 , be careful with this info as I am not sure and don't have an 84. Some sites show it crosses to 89019195 which is on rock auto and shows the 2724279 # and list's it as compressor mounted. https://www.corvettecentral.com/c4-8...igerant-454645
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Last edited by Vets-Vet; Aug 17, 2024 at 08:00 AM.
I'm not an A/C expert, and I'm not near my car right now to look, but I don't ever recall seeing a switch attached to a Schrader valve. I'm wondering if somebody didn't improvise a fix.
Every one of those type valves or switches I've seen are screwed or clipped into the back of the compressor.
However, if you can wait until Monday I'll look at mine and see how far off the mark I am.
I see GM 2724279 high pressure cutout fan switch 84-96 , be careful with this info as I am not sure and don't have an 84. Some sites show it crosses to 89019195 which is on rock auto and shows the 2724279 # and list's it as compressor mounted. https://www.corvettecentral.com/c4-8...igerant-454645
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Thank you but that is a different switch that mounts in the case of the compressor. The one I’m looking for screws onto the schrader valve of the hose assembly on the compressor.
“I'm not an A/C expert, and I'm not near my car right now to look, but I don't ever recall seeing a switch attached to a Schrader valve. I'm wondering if somebody didn't improvise a fix.
Every one of those type valves or switches I've seen are screwed or clipped into the back of the compressor.”
Not sure what year you are looking at but on the 84 there is a 3 wire, 2 terminal plug that connects to the switch in question.
I don't ever recall seeing a switch attached to a Schrader valve. I'm wondering if somebody didn't improvise a fix
I know my 84 is the same as his, switch screws into a Schrader valve on the 2 hose assembly which is bolted to the rear of the compressor. Just like the pic already posted shows
Granted I only know it's a schrader valve since dad snapped mine off flush and the guts of the valve stayed with the sensor
Last edited by flannel_man; Aug 17, 2024 at 09:13 AM.
If you are unable to locate the exact switch you need(discontinued??), then any high pressure switch of any make or model will work with a thread adapter fitting. There are a multitude of venders(eg. McMaster-Carr) that probably have what you need for 5 or 6 bucks. I believe the thread sizing for a Shrader valve external thread is 8V1-32. I include the following link for visual.
If you are unable to locate the exact switch you need(discontinued??), then any high pressure switch of any make or model will work with a thread adapter fitting. There are a multitude of venders(eg. McMaster-Carr) that probably have what you need for 5 or 6 bucks. I believe the thread sizing for a Shrader valve external thread is 8V1-32. I include the following link for visual.
I had that in mind should my search becomes fruitless. NAPA has the OEM switch which I ordered and should have in a few days. The biggest thing to me is the cutout pressure should be the same as the original.
I had that in mind should my search becomes fruitless. NAPA has the OEM switch which I ordered and should have in a few days. The biggest thing to me is the cutout pressure should be the same as the original.
I think that most automotive HP switches are relatively the same. Off the top of my head I would say around 450 PSI as a "high" for most systems. Shouldn't be a concern. JMO.
EDIT: Upon further checking, my thread sizing for the Shrader valve is for a tire valve. An AC Shrader is different it appears. I have included a link that should have something you need if necessary.
FWIW, this question prompted me to look at my car, and lo-and-behold that's why my A/C doesn't work too!
In my defense, I've been chasing a bunch of other things and I wasn't even looking at this.
So, if anybody has figured out the replacement situation I'll be watching.
I also had a memory jog about another GM vehicle I own of a similar vintage, and lo, a similar switch is on the receiver/drier.
Which may be one of the reasons I never remember seeing such a switch on a compressor fitting.
Looks a bit different, but may work the same. Further research is needed.
**** I did a looksee at Delco's website and they ID P/N: 15-2151 as the A/C compressor pressure cycling switch. However, they do not show it as superseding the 100007057 (Delco 12-2352) that the parts book calls for. Again, further research.
Last edited by Kilobuck84; Aug 20, 2024 at 03:15 PM.
Reason: Added info
To close the loop on this in case someone else stumbles by looking for the same information. The original GM PN 10007057 has been discontinued and I have been unable to find anyone who reproduces it. I was able to find a NOS which fits perfect! Perseverance pays!
So, a question: Is there actually a Schrader valve under that fitting, or does the system have to be evacuated to change it?
I'm trying to source one myself, and if I do, I'll try to run some tests on it to determine cut-in/cut-out pressures. With that data, perhaps we can determine if something else can be substituted.
So, a question: Is there actually a Schrader valve under that fitting, or does the system have to be evacuated to change it?
I'm trying to source one myself, and if I do, I'll try to run some tests on it to determine cut-in/cut-out pressures. With that data, perhaps we can determine if something else can be substituted.
there is a small “tit” inside theater depresses the Schrader Valve on the service port. In the FSM I believe it gives the cutout pressure rating and function of the switch. I don’t have the manuals with me at the moment to check but I will look when I get a chance. The problem I had with all the other switches is the threads are too large to fit the connection on the line. It is a different size than the switch that mounts on the evaporator outlet line.
84 AC High Pressure Cut Out Switch (Compressor Mounted)
