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Expansion Valve Wiring

Posted: Fri Jul 05, 2024 8:55 am
by 3154tm
03 dodge caravan. when removing the expansion valve i did not note the orientation of the two pin electrical connector, it is not indexed and looks symmetrical. the male plug will fit and lock in the female connector either way. does it matter? thanks.

Re: Expansion Valve Wiring

Posted: Fri Jul 05, 2024 10:05 am
by JohnHere
I never saw an MVAC TXV with wiring connected to it. Are you sure the wiring doesn't connect to something else? Can you post a picture (maximum size 256 kb)?

Re: Expansion Valve Wiring

Posted: Fri Jul 05, 2024 3:54 pm
by 3154tm

Re: Expansion Valve Wiring

Posted: Fri Jul 05, 2024 4:49 pm
by JohnHere
Appreciate your posting the clarifying photos.

Guessing that it's just a convenient place to secure an electrical connector, that it's not associated with the TXV's operation, and that it doesn't matter which way it plugs in. Otherwise, the connector would be indexed to "mate" only one way.

Perhaps another Forum member knows something about it.

Re: Expansion Valve Wiring

Posted: Fri Jul 05, 2024 7:42 pm
by 3154tm
this is the old oem valve i removed with an interior pic below the "switch" on the body of the valve. going to apply 12v tomorrow and see what, if anything, happens.
https://ibb.co/XjCj6bW

Re: Expansion Valve Wiring

Posted: Sat Jul 06, 2024 7:43 am
by 3154tm
pulled the "switch" out of the x valve. it was packed in grease and appears to be a sensor of some kind.
https://ibb.co/p2xrVbG

Re: Expansion Valve Wiring

Posted: Sat Jul 06, 2024 7:44 am
by tbirdtbird
Agree with John. That sure is an odd way to engineer something. Maybe not enough coffee the day it was on the drawing board.
An expansion valve is not dependent on any electricity at all. That is actually part of the beauty of the valve, it is pressure dependent only.

Old time steam locomotives used a similar valve

Re: Expansion Valve Wiring

Posted: Sat Jul 06, 2024 8:19 am
by 3154tm
apparently, the "switch" is an evaporator temperature sensor.
https://www.chryslerminivan.net/attachm ... jpg.45089/

Re: Expansion Valve Wiring

Posted: Sat Jul 06, 2024 8:40 am
by tbirdtbird
Thanks for that, those are usually a sort of frost switch with a pigtail tube inserted into the evap. Maybe not such a bad idea after all

Re: Expansion Valve Wiring

Posted: Sat Jul 06, 2024 1:19 pm
by JohnHere
I had that in the back of my mind as a possibility.

Ostensibly, it senses the temperature only at the TXV, not at the evaporator, which to me is of greater importance to prevent ice-up and blocking airflow through the evaporator. Leave it to Chrysler Corporation (Stellantis) to design-in something unconventional.