Automotive Air Conditioning Information Forum

Hello AAC Forum. New person with limited A/C knowledge seeking some help if possible.

I'm in the process of changing all components except the evaporator on my 1987 Dodge Ramcharger and have ran into an issue.

Original system was R12. Changing to R134A.

The issue is the low? limit switch. Assuming "low" limit switch as it is on the return line from the expansion valve/evaporator.

The original one on the original hose was installed on a Schrader valve right at the expansion valve going into the evaporator. Just screws on, presses the valve, and worked from there.

The new hoses are the same as the old hoses with a Schrader valve attachment in the same location.

So the valve must be R134A pressure I'm assuming. And it must be a female connection to mount on a Schrader valve. (I'll try to attach a picture of the new hose with the old valve installed to give a better idea of the setup if needed.)

So that's my question. Anyone have a link, model, recommendation for the right R134A, Female, low limit switch, and the right psi range, to install?

Thanks for any input.

(Tried to attach a picture but it says the file is too large.)

Figured out how to decrease image size on my end. Let's see if this goes through...

I am thinking you can use the same valve. But give the other advisors a chance to weigh in. And please be patient, it is a long holiday weekend

Understood. Thanks for the response. Much appreciated.

Wow, have not seen one of those big Mopar switches in a while.

I would replace it with the cycling switch from a 1988-1993 Ford F-150. Same mounting, with a valve depressor.

You will need to buy the mating connector pigtail for the Ford switch. Both are easy to find.

The good news is the ford switches are adjustable, so you can set the cycle point for any pressure that works for you. The Ford switch is available pre-set for 134a as well.

Thanks for the reply. Any particular model or part numbers available? Links if possible.

Thanks again.

Switch for 134a is a Wells WVE 1S15787

Connector Pigtail is a STANDARD MOTOR PRODUCTS S610

Both fit a 1992 Ford F150 pickup.

Your local auto parts store can cross reference those numbers to any brand they carry.

If you search either of those parts online you will find the usual sellers you buy from.

Thanks for your responses and help. Much appreciated. I'm a novice trying to get my old Dodge running and the A/C working as well.

Glad to help

Not trying to be cryptic, but that big online parts seller is in direct competition with the site sponsor on many items - so we don't post direct links to them here.

Small stull like that switch and plug are available from several sources.