OM606 AC compressor clutch - Page 2 - PeachParts Mercedes-Benz Forum

Phillytwotank · #16 06-29-2018, 04:34 PM

Thanks y’all for the replies. Update: the compressor spins freely 360 smoothnot notchy.
I unplugged the only wire connection that I could see on the compressor. Like a one pole barrel type thing on the upper right side just underneath the PS pump. Right?
13.5 volts on the wire with ac on max LO. About 8v with the climate off
Jugging my lead blindly down the plug hole I see OL or very low resistance on the comp side.
Also, I can hear a chirping so Nd coming from the clutch when the engine is running like a bad bearing.
Thoughts? Looking like a bad clutch ya think?

Zulfiqar · #17 06-29-2018, 05:05 PM

Quote:

Originally Posted by Phillytwotank

Thanks y’all for the replies. Update: the compressor spins freely 360 smoothnot notchy.
I unplugged the only wire connection that I could see on the compressor. Like a one pole barrel type thing on the upper right side just underneath the PS pump. Right?
13.5 volts on the wire with ac on max LO. About 8v with the climate off
Jugging my lead blindly down the plug hole I see OL or very low resistance on the comp side.
Also, I can hear a chirping so Nd coming from the clutch when the engine is running like a bad bearing.
Thoughts? Looking like a bad clutch ya think?

The one wire you see is to start the compressor, it gets 12V +ve from the pushbutton unit when refrigeration is commanded. the field coil is a 5 amp circuit.

the 8V you see is the bias voltage, and its for the unit to detect if the compressor clutch field coil is good or bad (and then shoot a code at you)

The chirping is always the belt, check for its age etc. the clutch makes a clicking noise when the pressure plate is pulled in and will hum as it starts up. The system is setup to immediately blow the fuse on the field coil if the pulley slips against the pressure plate.

To check the coil - use a multimeter set to ohms, red to plug on compressor, black to its body. - you should see about 2.5 or 4 ohms

Phillytwotank · #18 06-29-2018, 08:21 PM

Belt looks old. Shriveled and shiny. I am seeing no continuity through the coil. Verifying what the ccu trouble code is showing.

At this point I’m thinking replacing the coprocessor and clutch all together is a more straight forward path to repair. Better likelihood for a long term fix. I can get a compressor here tomorrow from my guy. Labor wise, I think I would rather replace the compressor than try to fiddle with the clutch only with difficult access.

Phillytwotank · #19 07-02-2018, 11:44 AM

I’m going to be swapping the AC compressor today. Easiest path to repair for me. Cost was not a big concern.

Can anyone point me towards a work instruction for that job? Looks pretty straight forward but I am used to using fsm for most stuff that I do which I have none for this car.

Zulfiqar · #20 07-02-2018, 12:02 PM

Quote:

Originally Posted by Phillytwotank

I’m going to be swapping the AC compressor today. Easiest path to repair for me. Cost was not a big concern.

Can anyone point me towards a work instruction for that job? Looks pretty straight forward but I am used to using fsm for most stuff that I do which I have none for this car.

make sure to get the upgraded model compressor, when you recieve it (and its not a genuine denso) remove the sump plug and drain the oil, fill with 5 oz, and spin it about 30 to 50 times, dump the oil, then fill with 6 oz of oil and install on engine. - replace all O rings, replace dryer and expansion valve too. (I believe MB also advises to use this much oil in it - dont put the oil into the line ports).

The sump plug is right next to the wiring connector on the compressor.

Phillytwotank · #21 07-07-2018, 10:56 AM

Thanks all for the info and advice. Got a new genuine denso compressor put in there, 5oz of oil in the sump, changed the dryer, left the expansion valve alone, put a new belt on, Charged up the refrigerant.... ice cubes!!!

freesoul · #22 07-03-2019, 02:42 PM

So my OM606 AC is working very intermittently- I found this thread and it appears the clutch may not be operating correctly. Is there any way to fix it possibly without replacement?

TIA

Phillytwotank · #23 07-03-2019, 04:29 PM

if your problem is indeed caused by your clutch... most simple and straight forward way is to swap the compressor. I think there maybe is a way to find a clutch and swap it but i decided that that would have been far more trouble.

Zulfiqar · #24 07-05-2019, 11:20 AM

Quote:

Originally Posted by Phillytwotank

if your problem is indeed caused by your clutch... most simple and straight forward way is to swap the compressor. I think there maybe is a way to find a clutch and swap it but i decided that that would have been far more trouble.

The field coil is sold separately by denso and is easy to swap out. It comes as a complete clutch unit with the hub, field coil, connector, pressure plate and some shims too.

freesoul · #25 07-08-2019, 11:40 AM

Quote:

Originally Posted by Zulfiqar

The field coil is sold separately by denso and is easy to swap out. It comes as a complete clutch unit with the hub, field coil, connector, pressure plate and some shims too.

do you have any links to the part?

Zulfiqar · #26 07-08-2019, 11:53 AM

https://www.amazon.com/New-Denso-7SB16C-Groove-Clutch/dp/B06XQTFHNS

Here is one example.

You need to search the compressor model on google rather than the car.

freesoul · #27 07-08-2019, 05:09 PM

Quote:

Originally Posted by Zulfiqar

https://www.amazon.com/New-Denso-7SB16C-Groove-Clutch/dp/B06XQTFHNS

Here is one example.

You need to search the compressor model on google rather than the car.

Thank you, I assume I need to find a part number on the actual compressor?

oilslick · #28 07-09-2019, 08:05 AM

The clutch went out on my ‘96 E300 at the beginning of Spring this year. The AC had been ice cold and I didn’t want to disturb the system so I opted to just replace the clutch. After reading about the interchangeability of some Toyota clutches, I headed to the local salvage yard. I pulled three or four clutches from various Toyota’s and even some Mercedes. I installed an almost new looking MB clutch onto my E300 and have never looked back. The clutches I purchased were cheap enough and the repair took an hour. I removed the PS pump pulley and the fastening bolts for the compressor and was able to tilt the compressor enough to remove the old clutch and install the replacement clutch. It’s performed flawlessly!

Also, the Toyota clutches that I pulled are identical in appearance to the MB clutch with the exception of the fused part and they will fit perfectly on the compressor. One only needs to modify the power supply connection.

Maxbumpo · #29 07-09-2019, 10:30 AM

Quote:

Originally Posted by freesoul

So my OM606 AC is working very intermittently- I found this thread and it appears the clutch may not be operating correctly. Is there any way to fix it possibly without replacement?

First, is there something else like the KLIMA relay that causes the intermittent operation? If you've got a spare automotive relay around, and some wire and three pins, you can bypass the KLIMA and any faulty signals to it (like the speed sensor on the back of the compressor). Search on this forum for KLIMA bypass relay to get the plans for how to do that.

Yes, that clutch can be removed leaving the compressor on the car and refrigerant charge in place. Remove the 10mm bolt from the nose, find the next size up bolt (for the threaded portion diameter). Screw that bolt in, it will push off the clutch plate (save the washer / spacer to set the gap!), and then you can pull off the pulley wheel with the bearing (may need a three-arm puller), and then you'll have access to the magnet if you need to replace that part. Getting the wiring pin swapped out from the three-pin connector will be a challenge. On the whole, this will be a big pain to do leaving the compressor in the car, but it is possible.

Maxbumpo · #30 07-09-2019, 10:52 AM

Another thought - there is a simple resistance test for the clutch coil - have you tried that? Also check the gap.