1998 Volvo S70 AC compressor not turning on.

pb49415 · Post by **pb49415** » 22 Jun 2018, 08:41

I don’t have any AC. A couple things I’ve noticed. First, I originally believed the system was overcharged. I purchased a gauge to check it. Next, I purged some 134 from the system. First thing I noticed was that it wasn’t freezing cold. Just warm gas. Next, I checked the compressor to see if the clutch was spinning. It was not. I bumped it while engine was idling and manually turned it and nothing. Any suggestions on a next step????

Thanks in advance,
Paul

pb49415 · Post by **pb49415** » 22 Jun 2018, 09:14

I just checked the gap. It’s at least 6mm.

Post by **abscate** » 22 Jun 2018, 09:17

Hmm - wrong gap. It needs to be about 0.3mm or 12 thousands of an inch

pb49415 · Post by **pb49415** » 22 Jun 2018, 09:25

What’s the difficulty level of adjusting the gap? I watched a YouTube video of Robert DYI and he just shows him prying the clutch face off. He’s got good access too. I don’t have that kind of access. Any suggestions on doing this?

Post by **abscate** » 22 Jun 2018, 09:32

Three methods of adjusting the gap

The Volvo official procedure - the clutch is removed and shims are added/removed to the clutch hub to adjust the gap. You remove shims to decrease the gap. With about $1000 of Volvo tools, it is possible to do this without lowering the AC but most of us have to lower it to re-shim. Easier on the -1998 models, the 1999 and 2000 are pigs...

The MVS way - instead of moving the clutch disc closer to the metal AC compressor hub face by moving shims, we put shims on the outside of the clutch disc and push it towards the metal face until the gap is in the space specification of ....(to be double checked and inserted here)

This is called the bread clip fix and was later superseded by a World Famous Biologist to the Zip tie fix.

: AC Clutch Gap; Screen Shot 2018-06-22 at 11.33.12 AM.png (80.73 KiB) Viewed 2015 times

pb49415 · Post by **pb49415** » 22 Jun 2018, 10:12

Before I install the zip ties and waste time doing so, shouldn’t the clutch engage by using a push stick to get it closer to the pulley?

Post by **mecheng** » 22 Jun 2018, 13:20

Short the pressure sensor for a couple of seconds on the a/c line, does the compressor engage. If so, you have a pressure problem, you may have purged too much. If the pressure is too high, likely you have air in the system and not pure freon. A good idea would be to evacuate with a good vacuum and charge again so you can verify the amount.

pb49415 · Post by **pb49415** » 22 Jun 2018, 17:39

I think I found a little problem.......the wire connection to the high pressure port was completely severed from the sensor. When I reached down to disconnect it. Must have been broken before I got the car a few years ago. I’ve never used the AC. A least the car was essentially a trade for a dirt bike, so it didn’t cost anything out of pocket. Not looking forward to forking out the $$$, but it’s necessary.

. From my understanding, the sensor unscrews from the Schrader valve, correct?

pb49415 · Post by **pb49415** » 22 Jun 2018, 18:12

My next question is: since this connector is a 3 pin, how do I jump across to test? Which two terminals or 3 do I connect?

Post by **abscate** » 23 Jun 2018, 03:44

I put some info in the other thread. It’s a resistance measuring plug, not an on off so jumping it won’t help. It needs to send good info back to the ECU to convince the ECU to turn on the AC

Use the high pressure switch part number to search

30767231, 8628563

But it should be near the top of the Forum