I'm tinkering with my '64 F250 that I picked up last year from a neighbors estate. It has an FE motor with non-working ac. I am trying to get some info on it: year/era and what some of the wires are for.
There are a white and black wire going into the evaporator. If i connect power to the black the fan blows air. White wire??? Neither are connected at this time.
There is a switch in the dash above the evaporator. It has power in and a wire out that may have been connected to the compressor. It also has a heavy bare wire out the back that is not connected to anything but the end is slightly flattened like it was crimped to something. That wire is soldered to the back of the housing. It is labeled "OFF L M H"
Thanks for any info on understanding this system.
john

 

Here's my guess: Mark IV is an aftermarket brand and Escort may be it's model name. Air conditioning was a dealer installation back in those days. York compressors were one of the two brands (Tecumseh was the other) used by Ford back then. The "1-64" on the compressor data plate suggests that's its birth date. The switch mounted above the unit in the dash looks suspiciously like a fan switch (Off, low, medium, high) which may have been subbed in if either the a/c fan switch or the heater fan switch failed. I'm sure you know tht an FE motor was not OE for a '64 model year truck. I may be completely wrong, but then again some of this may be a good guess.

 

The door plate says that the truck originally had a 292 in it. The Current motor according to casting #s is from '67-'68. The switch maybe to control the compressor. One of the wires in the back looks like the one broken off on the compressor. The switchs on the fan unit and heater work. I pulled the switch out from behind the dash.





I can't figure out the wire out the back. It's almost like a thermacouple wire and is about 2' long and just tucked up under the dash

 

The dash switch is the temp control switch. The Bare wire is not a wire but the temp sensor for the switch. Obviously the temp control switch in the unit went for a crap and it was replaced with that one in a remote location. I Believe that switch and the face plate is out a JD tractor.


If it is like other under dash units.
One wire will be the power feed to the fan, one wire will be the power feed to the to temp control switch, and one wire will feed the compressor clutch from the temp control switch.


Since your unit has a remote temp control switch it is safe to assume that temp control switch in your unit went for a crap and the remote one was installed. So instead of the power wire for the temp control switch going to the under dash unit it went to the remote switch and that fed the compressor clutch.


Since you know what wire is the blower fan. Check for continuity between the other 2 wires while operating the temp control switch. you should have no continuity at OFF and at the higher temp settings (provided it is not really hot out) and have continuity at the lower temp settings (provided it is not cold out) if it does not do this it will be safe to assume that the switch in the unit went for a crap. Hence the reason for the remote switch.


If the **** off the under dash unit for the temp control fits on the remote temp control switch then that remote switch should be able to be installed in the under dash case.


FYI that remote dash switch is still available.

 

Whats the availability of R-12 in Arizona? Hard to find in California and very expensive..

 

Thanks for the info on the switch.
As for R-12, I think it's the same in az. Good luck finding it if you need it. Most likely easier to do a conversion to 134.
This system hasn't been used in years and I'm just checking it out for fun.