Gen 2 A/C System Differences between '93,'94, & '95

[FOMOCOTOSHO]

Can anyone tell me what is different about the A/C's on the 93 ATX vs. the '94 and '95 ATX?
I have a '95 ATX I bought that is missing the high pressure switch connector entirely from the harness that plugs into the side of the A/C "muffler" located behind the radiator in front of the engine. So I have looked at a couple other SHO's in the area for parts cars to pull parts from & use it as a diagram to figure out what I need.
When I looked @ the'94 ATX everything was exactly the same. However when I looked at a '93 ATX, there was no high pressure switch located on that muffler behind the radiator. This '93 I can get for much less $$ than the '94 I looked at but I'm worried the A/C Systems are different and it won't have the parts I need. I looked close and there's definitely something different about them.

Does anyone know what the difference is with the '93's and where the high pressure switch is located on a '93?

I would appreciate any help you could provide asap. Thanks!

THanks!

 

[Mr Anonymous]

R-12 systems didn't use a high-pressure cut-off switch, R-134A systems do.

'89-'93 cars were R-12, '94+ are R-134A.

It sounds like someone swapped a '93 drivetrain and harness into your '95.

 

[FOMOCOTOSHO]

Thanks for the info Mr. Anonymous. I'm not so sure someone swapped the drivetrain & harness because everything else is perfect & works fine. What else could I look for to verify differences in a '93 vs. a '95 to see if this is true or not? My compressor & lines are all original and say R-134a on the compressor so I don't think it's been swapped. I think someone just cut off the connector or that part of the harness.

 

[Mr Anonymous]

Maybe just the harness was swapped then.

Looking perfect and working fine doesn't mean that someone hasn't replaced one or more major components including the drivetrain. I've done countless drivetrain swaps where even someone from the Ford assembly line wouldn't be able to tell it wasn't factory.

Does your A/C work?

A/C parts from ATX cars are all 100% interchangeable. There are differences between the R-12 and R-134A parts, but they will all work with each other if you tell them to.

 

[SHOZ123]

When I parted out my '93 it had a R134A system in it and was identified by a tag on something under the dash.

It was a rebuilt car though and that may be why it had the newer system in it. '93 was the change over year and IIRC the compressors had some sort of color identification on them. Can't find the info now though.

 

[rubydist]

The 93 wiring will work on the later cars - the high pressure switch is normally closed and only opens if the pressure gets too high. There is a slight risk of compressor damage due to overpressure, but it still has the over-pressure relief valve on the lines, so you still have that protection. My 95 mtx conversion has the high pressure switch in the harness, but not connected to the line, because the line is from a 93 car so there is no port - it works fine.

The only other apparent wiring difference under the hood is the wiper motor connector is different between 93 and 94/95, but that is part of the dash harness.