its time to seperate the mopar men from the boys

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mikess68

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the small switch located on the side of the evaporator core. it has a tube running to the core. it probably is the cut off switch to monitor the temp and not let it get too hot or cold (freeze up) so. will the air work without it? will it get too cold and freeze up, or stay too warm and not cool enough, or have no or little effect at all. so... what do you think and what do you KNOW> ?? im asking cause i don't know.
 
I believe the switch you are referring to is a pressure switch, it shuts down the A/C when the freon gets too low.
 
If it has a small tube going to a disc shaped valve, that's a capillary tube to control the expansion valve(controls the freon to the evaporator). If it has wires coming out of it I'll have to investigate it further. It's been a while since I had my hands on this stuff. Kev
 
Sounds like the compressor cycle switch, keeps the evap from freezing up, you need one but it should be replaced as they get real sensitive when old and cycle too often
 
ok, sorry, left this out a small copper tube runs from the ac dryer itself and is attached to the box under the hood. it has a electric switch on the end 7 inches from the dryer. it is attached to open and close a door on the box, which appears to be a internal air/external air source. maybe like Max air is on todays cars, or maybe let in outside air to keep the coil from freezing over? dont know. it has been hooked(solder) to the unit through the box and there for can not be removed without terminating the switch. dryer can not be removed from box without unattaching the switch tube . stuck at this point. can't take the dryer out to check, without cutting off switch. don't know if switch is necessary. and if not necessary, should that door be open or closed. (could hook up a choke cable to it and do it manually if need be) thats why im looking for info. looked up parts and the dryer does not show that switch.
 
What year and model car are you asking about? Is it OEM factory A/C or "add-on"? Any chance you could post a picture?
 
sorry for the fuzzy pic, cell phone. it is factory air, im the first to touch it in decades. the switch comes out in the lower left of the pic where it is soldered to the core. you can not remove the core from the box due to the tube being attached (without cutting the tube) it is attached by a copper tube. it has 2 elect connectors on the switch and it pulls or pushes a cabel that opens a door on the heater box. ac switch.jpg

ac switch.jpg
 
the line that runs into the coil, terminates in a couple of holes drilled through the core. it just slides out. it is a temp sensor that transmits temp to the elect switch. tks for everyones help. thought this might help. :)
 
Where do you get a new from? On my 65 dart the guy who had it before me used a jumper wire. I would like to find a new one.
 
outside of buying a coil and using that one or finding an old mopar with air and robbing it. i do not know. it was not hard to remove once i got over the nerves of pulling something that not know what it was. my guess is that it is a copper wire and runs to the switch that transfer cold to the switch. might be nothing but that. i noticed that the ground wire on a house is about that size. its only use is to turn off the air if the coil freezes up from lack of circulation. it will run without it. sorry could not help more. mike
 
We STILL don't know what year/ model you are working on

That is the "evaporator temperature control switch" and the cap tube will be slid into something, probably another blind tube, which may be full of grease, on/ in the evaporator. Unless the cap tube is rusted/ corroded in place, it should pull right out of there.

You can indeed temporarily bypass it, but you'll have to watch the coil for freeze-up.

Here's how a switch like that works. That "wire" is a sealed tube, full of some sort of gas, depending on the temperature. Higher temp means the gas expands, and bears against the diaphragm at the switch, so in reality, it's actually a pressure switch. Some in the refer industry are adjustable, and in fact a commercial refer pressure switch often looks exactly like a pressure switch, except the pressure switches come with a 1/4 flare nut (usually) and the temp switches have a sealed "cap tube" just like the one on your evap.

From the '72 shop manual, which you can download on this site:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download


rba3ig.jpg
 
Well I took the unit apart and found the switch just need clean. I test it and it works know. Yeahhhhhh
 
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