Anybody have working a/c?

[VirginiaF1]

My '88 with R134 runs the coolant temp about 35F hotter with a/c activated. (205F on a 95F day)
Same day, same temp but a/c off sees 170F during same conditions.
Hmmmm....

Vent temps are about 30F less than ambient air temps..

[Phantoms]

Mine hasn't worked for the 5 years I've had my 90 S2. I've never even looked at it. I just try to drive at night down here in Georgia.

[veleno]

It works and is nice and cold when there's freon. A day later after the freon has leaked out of the compressor it's useless. If I don't sell the car I'll fix it.

[Bradical]

Originally Posted by VirginiaF1

My '88 with R134 runs the coolant temp about 35F hotter with a/c activated. (205F on a 95F day)
Same day, same temp but a/c off sees 170F during same conditions.
Hmmmm....

Vent temps are about 30F less than ambient air temps..

Sounds overcharged. This would cause the high-side pressure to run elevated, thus raising your condensing temperature and making the air entering you radiator hotter than ambient. It would also elevate your suction pressure, which would raise the temperature of the evaporator and cause poor cooling effect.

It could also be an inefficient compressor (leaking valves), but overcharging the system is probably more common.

[Alexk]

How much am I looking at for r134 conversion? Freon illegal where I live, not sold anywhere.
Might leave it as is. My back is always soaked when I get to work though, ah well. The leather seats don't help I suppose.

[Tom944]

I replaced the compressor 2 years ago and refilled with R12. My first time working on ac but I had a friend with most of the tools. Has been working great since. Only issue is that it massively speeded up the dash cracks!

[pfarah]

Alaxk,

134a conversion isn't very expensive. I had a local ac guy charge me about $60.00 labor. I think it's simply a couple of Schrader valve replacements (low side with blue cap and ?), a couple/few new o-rings, new drier, pressure valve, and a complete evac/refill of new refrigerant. You can get all the parts here on PP.

[JonA]

I have the compressor and it's bracket and the condenser that I removed two years ago. Free to anyone. Just pick up or pay the shipping.

Jon

[VirginiaF1]

Originally Posted by Bradical

Sounds overcharged. This would cause the high-side pressure to run elevated, thus raising your condensing temperature and making the air entering you radiator hotter than ambient. It would also elevate your suction pressure, which would raise the temperature of the evaporator and cause poor cooling effect.

It could also be an inefficient compressor (leaking valves), but overcharging the system is probably more common.

Top notch.. thanks mate!

[mazdaverx7]

I have 3 944's and the a/c does not work on any of them, lol

[Ericv]

I had mine converted from R12 to R134A just recently. It works great and was worth the money. It's a lot more enjoyable to drive it on hot days. The A/C now works better in my 86 944 than my 2005 Ford.

[Bradical]

R-12 uses a mineral oil while R-134a uses an alkaline benzine oil. You have to have the oil flushed out completely, evacuated and replaced. They usually would replace whatever o-rings possible because they will be saturated with the old oil, and mixing the oils turns it to an unpleasant sludge. That would be the bare minimum, WYIT approach would be to replace the metering device as well as rebuilding the compressor but that might not be necessary.

Does anyone know how the fan speed is controlled? Are the resistors located in the switch panel (meaning you'd have to replace the switch panel) or are they at the motor? My motor only works on 4...

[gtgt__bangbang]

the fan resistors in my '90 are located in the top of the Star Wars lookin air blower housing under the hood, just to front of the fire wall.

I think the good Dr Ferd inserted them in the housing & air flow to cool them a bit .

two screws

[Bradical]

Originally Posted by gtgt__bangbang

the fan resistors in my '90 are located in the top of air blower housing under the hood, just to front of the fire wall.

I think the good Dr Ferd inserted them in the housing & air flow to cool them a bit .

two screws

Thanks brother, I will pop them out for a look. I haven't found a write up for that yet, seems like it is a common problem. Maybe I should do one...

[mattdavis11]

Originally Posted by Bradical

R-12 uses a mineral oil while R-134a uses an alkaline benzine oil. You have to have the oil flushed out completely, evacuated and replaced. They usually would replace whatever o-rings possible because they will be saturated with the old oil, and mixing the oils turns it to an unpleasant sludge. That would be the bare minimum, WYIT approach would be to replace the metering device as well as rebuilding the compressor but that might not be necessary.

Does anyone know how the fan speed is controlled? Are the resistors located in the switch panel (meaning you'd have to replace the switch panel) or are they at the motor? My motor only works on 4...

134a needs PAG, Polyalkylene Glycol, and you don't have to flush out the mineral oil if you don't want to. Nor do you have to change the drier.

When I replaced the shaft seal, I added 2oz of PAG 46, sucked it down and filled it up with R-134a. Been blowing high twenties for about 10 years. OE all the way except the seal, and a low side adapter.

[Tom944]

I agree. Mineral oil in non-miscible with R134 so it just sits in the system at low points doing no harm. I added ester oil when I refilled with R12. This is compatible with both so I can just top up with R134. Garages won't do this because of their machines but I don't believe there is any chemical reason not to mix them.

[gmorken]

Originally Posted by JJR512

I have an '86 NA as well. Mine works, but it's very weak. It also lowers the idle rpm about 200, not sure if that's normal or a symptom of being low on Freon or something else.

JJR512 - that 200 RPM drop is normal when running your AC compared to it being off...

[PorscheChef]

I have a/c in my 89, 88, 85, and I am about to get my 87 n/a charged.I just put a good compressor on it.

[gtgt__bangbang]

brad no its a few screws. lets do a deep dive to flush the evaper.
actually thats done, just waiting ot leak check to wrap it up.
would NOT want to tear out the StarWars stack again, its sticky.

[Bradical]

The series resistor in my car is beyond saving... The bimetallic safeties are completely crumbled.