1999 Volvo V70 AWD XC, AC works for a little while, then hot

Post by **Ozark Lee** » 16 Jul 2007, 12:39

If the gap is to small I think the clutch will tend to drag a bit and cause excessive wear to the friction material.

The flashing REC and AC lights really aren't tied to the clutch problem but they do indicate another fault in the ECC system. Unfortunately, on a '99, there is no way to find out what it is mad about without using a Volvo Scan Tool to pull the codes. The most common problem is dust and lint clogging the small fans on the cabin temperature sensors.

...Lee

awbooth · Post by **awbooth** » 17 Jul 2007, 05:58

Well, I did everything you said and I was able to remove the clutch!! BUT..., I was surprised to find only one shim in the clutch shaft, not three. I scrapped away with my pointer tools to make sure they weren't siezed on the bottom of the clutch or stuck to the pulley wheel area where the clutch mounts to. Strange, I was able to file down the .09mm shim to get a gap of .04mm. I haven't tried to run it on a real hot day though. I have a photo I will try to attach of my compressor. I've read alot about this thermal switch, bypassing it etc, etc. I checked both sides of my compressor and the only thing I found is a hex head type nut on the side of the compressor... inside the nut is an allen wrench bolt. No wires that look cut or any kind of thermal switch wiring. I'm confused, if there is no thermal switch, what is telling my compressor to shutoff at high temp? I hope filing down the one shim that was in there works.
To comment on your advise on the cabin sensor fan, I removed it from the car to clean it with my air compressor, I ended up taking it apart to investigate and broke it. 2 questions, where can I get a new one cheap and will the ac work without it plugged in? Does the cabin sensor control by 66 degree to 78 degree temp. controls on the dash? Thanks again for everything, I will try to post the photo. The nut I described is greenish. There is one black wire rapped in a white plastic casing that clicks into a metal clip on the compressor, I'm assuming that's 12volt power.

http://img115.imageshack.us/img115/77/v ... sorjv6.jpg

Anthony

Post by **Ozark Lee** » 17 Jul 2007, 07:38

Here is how it should be. See item 6.

http://www.comteche.com/free-image-host ... e79299.pdf

As far as you cabin sensor goes, even broken I would plug it back in. The temp readings won't be accurate but it will be closer than not having a sensor at all. Try erievovo.com for a replacement.

...Lee

awbooth · Post by **awbooth** » 17 Jul 2007, 08:18

Looks like someone bypassed the thermal sensor completely before I bought the car. I've only had it for about 3 months. Any suggestions on what I should do? It looks like the greenish looking nut I emailed you is the thermal sensor. Should I remove it or will I loose refrigerant? Just curious, how can I get a break down of parts like the compressor like you sent me? Pretty cool!! Any thoughts on the clutch having only one shim instead of the three it should have had?
THANKS AGAIN!
ANT

Post by **Ozark Lee** » 17 Jul 2007, 08:37

I would just leave it. Bypassing it is a common thing to do. I'm not sure if the system opens up or not if you take it out.

As far as the diagram goes: click.

...Lee

awbooth · Post by **awbooth** » 17 Jul 2007, 13:18

thanks for all your advice. Should I replace the clutch plate and compressor to fix the problem correctly? If the thermal sensor was bypassed along time ago, why did the compressor still shut off at high temps? After looking at the compressor blueprint you sent me it's obvious wires are missing off the sensor. I'm surprised the compressor hasn't fried already?? What is shutting off the compressor if the sensor was bypassed? the relay heating up?
On a side note, my viscous coupling was bad when I bought the car. found out at the dealer after getting a recall done. i have been driving around with no rear drive shaft for months, taking off the dshaft bypasses the problems with awd, nice, real nice!!!! Again, thanks alot. Are you a volvo mechanic? just curoius'
ant

Post by **Ozark Lee** » 17 Jul 2007, 14:28

Should I replace the clutch plate and compressor to fix the problem correctly? If the thermal sensor was bypassed along time ago, why did the compressor still shut off at high temps?

The thermal switch is really only half of the equation, it tries to protect the electromagnet coil from overheating.

Once the gap gets too wide the electromagnet on the clutch simply doesn't have enough "umph" to pull the clutch in. If the reshim job doesn't work then the compressor/clutch change is the logical next step.

Are you a volvo mechanic?

No, I'm an electrical engineer but I have an 850 with 190 k on the clock and it seems that everything that can go wrong with an 850 has gone wrong with mine. As long as it isn't the middle of winter I actually enjoy working on cars. The Volvo is a lot more fun to work on than the Porsche that is my current project with my daughter.

...Lee

Frink1234 · Post by **Frink1234** » 18 Jul 2007, 20:30

Here is a breakdown for those of you NOT mechanically inclined enough (like me) to tackle the gap adjustment work on the A/C compressor clutch.

1. Remove A/C compressor and adjust clutch - 3 Hours labor @ $75/hr
2. General A/C servicing - $75
3. Freon added - $24

Total PLUS TAX = $344.99

For me anyway, it was worth it to get my A/C working again.