A/C Trouble

Scott R · Scott R's Garage

Found out that my mixing flap rod had a broken clip, I'll replace that no problem, but my A/C is still dead. The switch lights up, and the fan kicks on. But no power to the compressor!?! Any ideas?

lordgrommit · 03-13-2001, 04:46 PM

Prob out of gas in the system. I have the same problem except my switch is missing I'm going to convert to 134a. there is a pressure switch that will tell the system not to turn on the compressor if there is no pressure in the system. take off a cap and see if there is any pressure on the valve (kind of like a bike tire valve press the middle and see if anything happens)

matt

Scott R · Scott R's Garage

Just checked this, and I found the switch just below the inspection window. I checked it, pulled the wires off and tried it, then jumped the hot across and it still didin't start up. Looks like I have plenty of pressure in the system. I also don't have any vacume at the heater valve, but all the vac connections are good, and the fan only works on position "4" DAMN THIS THING!

kukunaokala · 03-13-2001, 06:28 PM

The switch supplies power to the clutch (I'm using the Haynes manual). The only thing left would be check continuity between low pressure switch and compressor clutch and terminal ends and wires. As for your fan, hope someone can give you the location. The year and model (we should know the make) would help. Good luck, Neal

Scott R · Scott R's Garage

It's a 85.5, when I had a shop doa check-up on it a year ago they wrote down next to the "A/C" catagory that there was no vacume at the heater valve. This would not have anything to do with it would it?

ckrough · 03-14-2001, 07:57 AM

lorgrommet.

Watch that conversion. My father works on Freons at DuPont and said that R134a will eat the seals in an R12 system. Tons of companies sell conversion but they don't tell you that your seals will go in a year or two. I haven't heard of any experiences with it, but he did tell me that once when we were talking about freon conversions.

My A/C is also dead, will be charging it next week, hopefully that's the problem...and it doesn't have a huge leak.

------------------
Chris

90 944 S2 Cab, Guards Red

no1biscuit · 03-14-2001, 10:05 AM

Check to make sure the compressor is plugged in all the way. Mine came partially loose and stopped working.

Scott R · Scott R's Garage

So, about the vacume problem. There are two vacume units inside the glove compartment area, (glove box out) and these appear to direct ported vacume back to the heater valve. I have vacume at both of these units, but they don't seem to be opening up to redirect vacume, anyone every have one of these things fail?

pst · 03-14-2001, 02:26 PM

You may have a bad clutch coil. Check for condinuity between the clutch hot wire and ground, also check the ground connection for the coil. The one on mine broke off at the connector. As for the R134A conversions, I used one of those cheep kits on my 924, my plymouth Voyager and my wife's eclipse. All are functioning just fine. This next summer will be the 4th summer on my 924, and it is still holding up fine. It's a big job to change all of the hose seals and to change the hoses to barrier type. I am doing this on my 944 only because it is completely apart anyway.

Scott R · Scott R's Garage

Ok on further investigation, I found that there is switched power to the freon sensor, I was just not picking a good ground when I was measureing it. So I have +12 on the forward post and +0 on the rear post. So I assume by the other posts that I am out of freon. Withought having a high-tek freon leak tester, where doe these things usually leak from? And how should I test it with the compressor disabled. Or is it time for a shop?

scottewid · 03-15-2001, 10:00 AM

I think the only way to find the leak is to have a shop charge it (since you can't buy r12 yourself) and put flourescent dye in it. You run it on and off for about a week, then bring it back and the shop will shine a black light on connections, hoses, condensor to pinpoint the leak. If it's in your evaporator, though, I don't know how they'd see it unless they ripped the dash apart. Also, doesn't Porsche use porous lines that leak out freon as a matter of course. Does anyone know how long before you need a recharge due to this "normal" leakage, assuming no other leaks elsewhere?

Scott R · Scott R's Garage

well I still have a valid freon handeling license, and found that you can buy R12 right off EBAY, good prices to. When we used to check this in the shop we had an electronic tester that beeped when you ran it over a leaky line. If it just leaks out due to porus hoses then thats great! I'll just recharge it. But I would think that it would have to leak a whole bunch over 14 years to cause that sensor to go off. But if thats normal, and if anyone knows if thats normal, then please respond!

lm6y · 03-16-2001, 06:12 PM

Scott R. that is normal for the switch to shut the system down. If it hasn't been charged in 14 years, that's pretty good. When you go to get recharged, they will have to do a vacuum test on the system. if it fails, by law, they cannot recharge it. But, if it hasn't been charged in 14 years, and is just now not working, it should hold vacuum.

As for the freon lines having holes to bleed off the pressure, it's not true. The holes on the outside of the rubber lines were used to measure length, and only go through the outer casing.