960 stuck AC clutch - Page 2

mschultz373 · 08-02-2022, 02:37 PM

im getting 0ohms from the green wire off the compressor to ground (case of compressor and tried negative battery terminal).

a reading of 0.00 indicates that there's a short in the windings?

apachechef · 08-02-2022, 03:02 PM

.that scotch lock is suspicious(all scothclock s are), look around there for a short.

Khrrck · 08-02-2022, 04:12 PM

Quote:

Originally Posted by mschultz373

im getting 0ohms from the green wire off the compressor to ground (case of compressor and tried negative battery terminal).

a reading of 0.00 indicates that there's a short in the windings?

Very likely. Unless the green wire itself is somehow shorting to ground OR it's somehow still connected to harness (doesn't look like it from your image) and THAT is shorted to ground.

However I'm surprised it's entirely 0.00, usually you get at least a tiny bit of resistance from the connections and wires involved

mschultz373 · 08-02-2022, 04:21 PM

I'll try to monitor the amperage draw once I get the tool Kyote recommended - that might reveal something new.

Otherwise, does that mean a whole new compressor is needed? Or could I replace just the AC clutch?

I have a compressor from a 94 940 - would that have parts that could work on this 960?

2manyturbos · 08-02-2022, 05:16 PM

The compressors are completely different, 940 versus 960. I doubt there’s anything you could use from a 940 compressor to make that 960 compressor work again. And yes, the reading you are getting indicates a dead short as long as you know how to use the ohmmeter you have. That’s why you are blowing 15 amp fuses. You already know what the problem is at this point, replace the compressor.

GTJordan · 08-02-2022, 07:41 PM

Quote:

Originally Posted by mschultz373

I have a compressor from a 94 940 - would that have parts that could work on this 960?

4cyl and 6 cyl compressors are different. 92 6 cylinder is different than the 93 and up compressors.

Jordan

mschultz373 · 08-02-2022, 07:50 PM

is there a brand that is best for 960 compressors? And other components that should be replaced with the compressor?

Is this a job for DIYer? I do not have equipment to evacuate freon from system and all....

GTJordan · 08-02-2022, 08:02 PM

Quote:

Originally Posted by mschultz373

is there a brand that is best for 960 compressors? And other components that should be replaced with the compressor?

Is this a job for DIYer? I do not have equipment to evacuate freon from system and all....

If you have a 92, I've got a reman'd compressor.

The compressor itself is DIY. But evac, vac and recharge would be more challenging.

Jordan

philski o'flood · 08-02-2022, 09:15 PM

Quote:

Originally Posted by GTJordan

The compressor itself is DIY. But evac, vac and recharge would be more challenging.

Jordan

especially for a guy with a cast on his left wrist

apachechef · 08-02-2022, 09:18 PM

check the scotchlock, there shouldn't be three wires, just one, from the clutch to the factory harness. that third wire could have shorted to cground, causing ALL the sxs

lookforjoe · 08-02-2022, 09:44 PM

The clutch can be replaced without removing the compressor. If the compressor was seized, the belt would have melted when the clutch coil engaged the compressor.

Clutches are pretty much all the same, difference being serpentine vs. V-belt - so, the 940 clutch wouldn't work. Clutches can be had for well under $100 online

Did you try powering the clutch from a jumper wire to the battery? You can do it through a 15a fuse, if the fuse blows the coil is no good, if the coil is good, it will simply stay engaged.

That scotchlok needs to go - that is no way to repair a broken wire

mschultz373 · 08-02-2022, 10:54 PM

I jumped the AC Clutch from the battery and it didn't blow for 30 secs. I could test it longer, and the car was just at idle.

I'll investigate the scotchlock tomorrow.

lookforjoe · 08-03-2022, 07:38 AM

Quote:

Originally Posted by mschultz373

I jumped the AC Clutch from the battery and it didn't blow for 30 secs. I could test it longer, and the car was just at idle.

I'll investigate the scotchlock tomorrow.

OK - so that sounds like the clutch coil is overheating. It is conceivable that the bad connection at the scotchlok is causing the circuit load to blow the fuse, so definitely remove that & proper splice the wire to retest. While you are at it, take a pic of the Volvo label on the compressor with the identifying numbers/manufacturer info

Did you note whether sweat developed on the accumulator or if the vent air temp dropped during that 30sec? Any untoward sounds from the compressor itself?

Without knowing whether there is a charge in your system, running the compressor for any length of time is not ideal. You can seize it if there is no freon/oil circulating.

mschultz373 · 08-03-2022, 11:40 AM

I know that the system is charged and was blowing cold (~35F) when operating properly before this issue arose about a week ago. that is with ambient temp outside over 85F. i do not have a gauge to put on the dryer port, but it would mean that all the freon would've leaked out in a matter of days. i can't say i know for sure about the oil level in the compressor.

to be clear, the fuse did NOT blow, i left the jumper wires in place for ~30 secs. sorry if I was unclear on that.

i will replace the scotchlock but after looking at it more i doubt there is a short or problem there. wires seem intact and OK.

apachechef · 08-03-2022, 01:00 PM

Quote:

Originally Posted by mschultz373

I know that the system is charged and was blowing cold (~35F) when operating properly before this issue arose about a week ago. that is with ambient temp outside over 85F. i do not have a gauge to put on the dryer port, but it would mean that all the freon would've leaked out in a matter of days. i can't say i know for sure about the oil level in the compressor.

to be clear, the fuse did NOT blow, i left the jumper wires in place for ~30 secs. sorry if I was unclear on that.

i will replace the scotchlock but after looking at it more i doubt there is a short or problem there. wires seem intact and OK.

Quote:

to be clear, the fuse did NOT blow, i left the jumper wires in place for ~30 secs. sorry if I was unclear on that.

a jumper wire has NO fuse, did you have a fuse between the battery and the clutch in series?

mschultz373 · 08-03-2022, 04:41 PM

yes, in series. wire to fuse to wire to AC clutch fuse block.

Khrrck · 08-04-2022, 12:13 AM

When you tested the green wire resistance to ground, did you have it disconnected from ALL car wiring? if not, do so and test again. I'm thinking maybe your A/C clutch wire is shorting to ground inside the harness somewhere, so if it wasn't disconnected from the harness you could have been measuring resistance through the short instead of through the clutch coil.

mschultz373 · 08-04-2022, 12:32 PM

I disconnected the bullet terminal that runs to the AC compressor and measured resistance from the AC compressor.

I took the scotchblok out and soldered the AC compressor wiring this morning - both the wire TO the compressor (from harness) and the wire that runs up to the AC clutch. It actually read 1.2ohms after completing this, but the ac clutch (again) blew the 15A fuse in a matter of seconds.

lookforjoe · 08-05-2022, 08:54 PM

Quote:

Originally Posted by mschultz373

I know that the system is charged and was blowing cold (~35F) when operating properly before this issue arose about a week ago. that is with ambient temp outside over 85F. i do not have a gauge to put on the dryer port, but it would mean that all the freon would've leaked out in a matter of days. i can't say i know for sure about the oil level in the compressor.

to be clear, the fuse did NOT blow, i left the jumper wires in place for ~30 secs. sorry if I was unclear on that.

i will replace the scotchlock but after looking at it more i doubt there is a short or problem there. wires seem intact and OK.

The freon can leak out in a heartbeat, if there is a rupture.

OK - so the compressor runs with the clutch jumpered directly to the battery (via fuse), but blows the (AC System) fuse when wired through the AC circuit, does that sum it up? Did you also confirm it blows cold under these conditions?

If that is the case, then the problem is elsewhere in the AC circuitry, not a fault with the clutch coil....

mschultz373 · 08-07-2022, 04:09 PM

i repeated the jumper wire thru 15A fuse to the AC clutch - it powered the clutch/compressor at idle and blew cold.

then I put a 15A fuse in - and the AC clutch engaged and air blew cold at idle AND driving. did about 5min at idle and then a 5min drive around the block. air blew cold the whole time - read ~40F with ambient temp over 90F (70%+ humidity) driving around 30-40mph.

my guess is there's some weird intermittent short in the wiring somewhere? will monitor and report back.

08-02-2022, 02:37 PM	#26
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	im getting 0ohms from the green wire off the compressor to ground (case of compressor and tried negative battery terminal). a reading of 0.00 indicates that there's a short in the windings? Last edited by mschultz373; 08-02-2022 at 02:43 PM..

08-02-2022, 09:44 PM	#36
lookforjoe Making Volvo Parts Fit Join Date: May 2008 Location: Rockland County, NY	The clutch can be replaced without removing the compressor. If the compressor was seized, the belt would have melted when the clutch coil engaged the compressor. Clutches are pretty much all the same, difference being serpentine vs. V-belt - so, the 940 clutch wouldn't work. Clutches can be had for well under $100 online Did you try powering the clutch from a jumper wire to the battery? You can do it through a 15a fuse, if the fuse blows the coil is no good, if the coil is good, it will simply stay engaged. That scotchlok needs to go - that is no way to repair a broken wire __________________ My XR July2013 - 446AWHP @ 8K rpm C30 AWD conversion 740 pickup thread Feedback Thread

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-02-2022, 04:21 PM	#29
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	I'll try to monitor the amperage draw once I get the tool Kyote recommended - that might reveal something new. Otherwise, does that mean a whole new compressor is needed? Or could I replace just the AC clutch? I have a compressor from a 94 940 - would that have parts that could work on this 960?

08-02-2022, 05:16 PM	#30
2manyturbos Moderator Join Date: Mar 2003 Location: Monroe, OR USA	The compressors are completely different, 940 versus 960. I doubt there’s anything you could use from a 940 compressor to make that 960 compressor work again. And yes, the reading you are getting indicates a dead short as long as you know how to use the ohmmeter you have. That’s why you are blowing 15 amp fuses. You already know what the problem is at this point, replace the compressor.

08-02-2022, 07:50 PM	#32
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	is there a brand that is best for 960 compressors? And other components that should be replaced with the compressor? Is this a job for DIYer? I do not have equipment to evacuate freon from system and all....

08-02-2022, 09:18 PM	#35
apachechef Burnt Sierra Madre Join Date: Jan 2009 Location: An obscure body in the SK system	check the scotchlock, there shouldn't be three wires, just one, from the clutch to the factory harness. that third wire could have shorted to cground, causing ALL the sxs

08-02-2022, 10:54 PM	#37
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	I jumped the AC Clutch from the battery and it didn't blow for 30 secs. I could test it longer, and the car was just at idle. I'll investigate the scotchlock tomorrow.

08-03-2022, 11:40 AM	#39
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	I know that the system is charged and was blowing cold (~35F) when operating properly before this issue arose about a week ago. that is with ambient temp outside over 85F. i do not have a gauge to put on the dryer port, but it would mean that all the freon would've leaked out in a matter of days. i can't say i know for sure about the oil level in the compressor. to be clear, the fuse did NOT blow, i left the jumper wires in place for ~30 secs. sorry if I was unclear on that. i will replace the scotchlock but after looking at it more i doubt there is a short or problem there. wires seem intact and OK.

08-03-2022, 04:41 PM	#41
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	yes, in series. wire to fuse to wire to AC clutch fuse block.

08-04-2022, 12:13 AM	#42
Khrrck Professional Amateur Join Date: Mar 2015 Location: Beaverton, OR	When you tested the green wire resistance to ground, did you have it disconnected from ALL car wiring? if not, do so and test again. I'm thinking maybe your A/C clutch wire is shorting to ground inside the harness somewhere, so if it wasn't disconnected from the harness you could have been measuring resistance through the short instead of through the clutch coil.

08-04-2022, 12:32 PM	#43
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	I disconnected the bullet terminal that runs to the AC compressor and measured resistance from the AC compressor. I took the scotchblok out and soldered the AC compressor wiring this morning - both the wire TO the compressor (from harness) and the wire that runs up to the AC clutch. It actually read 1.2ohms after completing this, but the ac clutch (again) blew the 15A fuse in a matter of seconds.

08-07-2022, 04:09 PM	#45
mschultz373 Board Member Join Date: Mar 2020 Location: dirty coast	i repeated the jumper wire thru 15A fuse to the AC clutch - it powered the clutch/compressor at idle and blew cold. then I put a 15A fuse in - and the AC clutch engaged and air blew cold at idle AND driving. did about 5min at idle and then a 5min drive around the block. air blew cold the whole time - read ~40F with ambient temp over 90F (70%+ humidity) driving around 30-40mph. my guess is there's some weird intermittent short in the wiring somewhere? will monitor and report back.