so i'm at a loss as to how to proceed

a/c compressor quit working, but i was able to un plug and hot wire it down at the compressor plug and the clutch engages and it blows cool but not icy cold.

I have 12V at the center wire of the three wire plug that goes to the electronic thermador box (???) thingy that bolts onto the side of the H valve.

I tried cutting and splicing the 2 outer wires (blue/white and brown) from that same device (as suggested on a post i read to bypass that temp switch) and still nothing from the clutch.

then i tried jumping the low pressure switch and that did nothing to entice the clutch to engage (i unconnected the 2wire plug and tried jumping it w/ a paper clip).

i'm kinda thinking thees directions;

so could it be simply low freon or some kinda safety switch?

should i hunt down r12 and see if i can make it take a can by hot wiring it again (will hot-wiring it even be necessary???)?


if i do that should i vacuum it and oil it?

it's hot in NOLA and i'd like to get the a/c cranking again

thanks for any advice

marcus

 

Sound a lot like the issue I was having with the A/C on my donor 93. I did pretty much everything you tried. Eventually I figured out it was the WOT (wide open throttle) relay on the drivers side inner fender that was shot. Replaced that and A/C is all good.

But if you jumped the compressor and it was not blowing ice cold...then I'd suspect that you were low on refrigerant, and there fore the low pressure cut out switch would not be allowing the system to operate.

But then you said you jumped the low pressure switch and it still did not turn on. So maybe you have other issues?

But I would try the WOT replay...and see if that gets things working again.

 

Sounds like the low pressure cutout switch is working. It is on the fender side of the H-block. Try putting everything back as normal, remove the connector from the cutout switch, jump across the two wires and see if the compressor comes on. If so, it needs freon. If not maybe a bad connection between the thermostat thingy on the side of the H-block and the compressor. There is another connector down by the compressor, it could be loose or corroded, but it sounds like low pressure to me...Mark

 

Sorry, I missed that you already jumped the switch. Check the lower connector for 12 volts. If there is 12 volts leaving the thermostat thingy, there should be 12 volts at the lower connector. I think it is the brown wire that should be hot. It is a pretty simple system and you should be able to find the problem. Also the compressor does not have to be spinning to introduce freon into the system...Good luck...Mark

 

thanks for the quick reply, gonna try and get up early and give this stuff a try. if i introduce "a charge" how do i find out what to use and can they be combined. I still have wqhat looks like the original schrader valves so is that r12 of freeze 12 or what??(any idea/i know its not 134(a))?

also should i look for 1 w? oil

thanks again

 

You can use r12 or any replacement. They have what is called an oil charge, which adds some oil with the freon. Since the system did not self destruct, the oil should be ok, if it wasn't low in the first place. JMartin has posted about a homemade freon brew made of propane and something else (can't remember right now). Search his posts and it should come up, it was pretty recent. You can buy r-12 on E-bay, not cheap...Mark

 

FYI
Intercooled variants have the cutout switch the drivers side of the expansion valve.
Jim

 

Thanks Jim, I suspected that from my own problems with the wrong expansion valve,,,Mark

 

Hydrocarbon Coolant. I can of IsoPro mountain fuel, and 14 oz of Coleman propane. (Driest we've found)

Components are 71% Propane, 29% Isobutane. (not butane)

Put in IsoPro first, followed by propane. If mixed, always withdraw from container as liquid, not gas.

Propane adaption to flare is easy. A Can top Freon piercer will work on the IsoPro with a little relief with a Dremmel tool.


hope it helps

 

If you have power to the thermostat thingy and no power at the lower connection, then the thermostat thingy is bad or a wire is open. Check for continuity of the wires. The good news is that you are dealing with a short length. If the thermostat thingy is bad, you can get them from this guy:

Thanks, Bob Schaetz @ East Texas Auto Air & Glass
1019 West Marshall Ave.,
Longview, Texas 75604
ph 903-753-0089
fax 903-753-0076
cel 903-720-1922

It was the only place I could find it...Mark