Looking for some a/c help

[Cornexav]

I've decided to try and resurrect my a/c, only problem I have is I have no idea what condition everything is in. My ranger is a 93 but it appears someone did a conversion, or at least changed the low side port to an r134a coupler. The a/c currently blows somewhat cold air only while driving 30+mph. Just wondering what people have for advice before I just try and buy all new r134a components and swap them in. Thanks in advance.

 

[RonD]

If the system still has pressure in it and compressor cycles on and off, then I would try just recharging it

 

[mikkelstuff]

I finally went with Enviro-Safe R12 replacement refrigerant for my '75 Ranchero. This refrigerant really cools well and the large propane/butane molecules do not ooze through my original AC hoses.

True enough, the stuff is flammable - but then so is gasoline.

Enviro-Safe Modern Refrigerant, Auto A/C R12 or R134a Replacement & Dye (6) Cans | eBay

Enviro-Safe&; Refrigerant with Dye is made of only the Most Pure, Quality, Refined ingredients available today. Enviro-Safe&; Refrigerant with Dye is different, because it is highly refined! Enviro-Safe does not contain the “rotten egg, sulfur, propane” odor. Enviro-Safe&; Refrigerant with Dye...

www.ebay.com

 

[Cornexav]

If the system still has pressure in it and compressor cycles on and off, then I would try just recharging it

So like I said it blows somewhat cool air, but I don't know if the compressor actually turns on or not. is there a way to test the compressor with a jumper wire?

 

[adsm08]

So like I said it blows somewhat cool air, but I don't know if the compressor actually turns on or not. is there a way to test the compressor with a jumper wire?

Start by turning the system on and looking at the compressor to see if it is turning on and off.

If it doesn't ever turn on turn the engine off and the key on and jumper the wires for the low pressure switch on the black tank back by the heater/evaporator box.

 

[RonD]

As said start engine, turn AC on and compressor should start to cycle on and off, it should do this even with AC off but turn AC on just to be sure

If its not coming on then either refrigerant has all leaked out, or compressor clutch is bad(unlikely)

Here's the problem, you can end up spending money on refrigerant you don't need and if there is a leak you lose that money, or if a part is bad and needs to be replaced then you also lose that money because system needs to be opened and you lose refrigerant

I would spend the money for an AC guy to test the system and tell you whats wrong, then YOU can replace the parts you need to instead of guessing at what needs to be replaced


AC systems are not complicate in how they work, the compressor COMPRESSES the refrigerant, I know duh, this makes the refrigerant very very HOT and under high pressure, which is "stored energy".
Then there is an Expansion Valve, when this HOT refrigerant is allowed to UNcompress/expand, it get VERY COLD as the "stored energy" is released
And you have AC
Now the compressor is either ON or OFF, there is no TEMP CONTROL for an AC system, the temp control in the cab moves the Blend Door inside the cab, that sends air from the fan either thru the Heater Core(HOT) or around(bypass) the heater core(COLD), or anywhere in between

AC system diagram here: https://www.2carpros.com/images/articles/original/ac-system-645.jpg

Home AC, refrigerators, freezers, ALL use the same system, compress the gas to heat it and then un-compress the gas to cool it
Repeat, lol

There are certain aspects like the "high side" pressure, and "low side" pressure that have to be in a certain range for the system to work, and not Burn Out the compressor or Blow Out a connection

An AC guy will have the high pressure gauges to test system and to see if system can even hold pressure, no leaks

You can learn all this and rent the gauges needed to test it, loads of videos on how to DYI automotive AC systems
Thats up to you

And as you may have surmised by reading the above, its NOT working above 30MPH, if AC Compressor is not cycling at idle, lol.

 

[Shran]

I finally went with Enviro-Safe R12 replacement refrigerant for my '75 Ranchero. This refrigerant really cools well and the large propane/butane molecules do not ooze through my original AC hoses.

True enough, the stuff is flammable - but then so is gasoline.

Enviro-Safe Modern Refrigerant, Auto A/C R12 or R134a Replacement & Dye (6) Cans | eBay

Enviro-Safe&; Refrigerant with Dye is made of only the Most Pure, Quality, Refined ingredients available today. Enviro-Safe&; Refrigerant with Dye is different, because it is highly refined! Enviro-Safe does not contain the “rotten egg, sulfur, propane” odor. Enviro-Safe&; Refrigerant with Dye...

www.ebay.com

An old Ford tech I know told me a story about someone charging the AC on a bus with propane and leaving it parked in their shop overnight.

It had a leak, and sometime that evening there was a spark, probably from an air compressor kicking on or something but it burned the shop to the ground.

Granted, that bus probably had a huge AC system and a lot of propane in it, but still. Propane technically is a refrigerant but it is absolutely NOT something I would ever use! Even a small amount, say 48oz like our RBVs hold is plenty to blow up your average home garage.

 

[Cornexav]

No ac systems aren't complicated, was just looking to see if anyone knew where I could get a wiring diagram of the ac clutch and switches alike, or if I should just swap everything out for like a 95 ranger ac system.

 

[RonD]

Sure, here is the 1994 HVAC wiring, 1993 will be the same

Compressor clutch is always grounded
Climate control in cab sends the 12volts from fuse 17 in cab fuse box to the Pressure switches, if both are closed then the 12v goes to AC/WOT cut off relay, which passes the 12volts when its OFF on to the compressors clutch

Fuse 17-------Cab control---------pressure switch------pressure switch-------WOT relay----------------compressor clutch

 

[Cornexav]

Well I jumped the compressor, clutch engages. There is voltage at the low side pressure switch but idk what it is supposed to be. Getting a vacuum pump and gauge set to try and evac the system. But that's for another day, now I get to figure out why I've lost about half a gallon of coolant in a day