97 E300 90mA battery drain - Page 2 - PeachParts Mercedes-Benz Forum

VW1300 · #16 12-16-2015, 08:41 AM

Quote:

Originally Posted by jay_bob

The PSE has a connection to the body CAN bus to perform these functions. I guess MB thought another SAM in the rear was overkill for these functions so they stuck them in the PSE.

Thanks - that knowledge may come in handy someday.

Jeremy5848 · #17 12-16-2015, 10:51 AM

Quote:

Originally Posted by tjts1

I should add that I installed a 150a alternator from an R230 and added a 4awg wire from the alternator to the + post on the driver's side inner fender so at least my charging system can deal with afterglow and bring the battery back up quicker than stock. We're taking the car up to Tahoe this weekend so it'll see a few cold starts below freezing.

I also added a 150A Bosch alternator to my '95 E300D (W124, OM606NA) and ran a second AWG 8 wire in parallel with the factory wire. It's not as low-Ohm a path as a single heavier wire but good enough for my use. The bigger alternator does a magnificent job of bring the battery back to full charge after the starting load. By the time I'm out of the garage the voltmeter is up to 13-point-something. Why MB didn't put something larger in their diesels of that era is beyond me.

tjts1 · #18 12-16-2015, 12:34 PM

Quote:

Originally Posted by Jeremy5848

I also added a 150A Bosch alternator to my '95 E300D (W124, OM606NA) and ran a second AWG 8 wire in parallel with the factory wire. It's not as low-Ohm a path as a single heavier wire but good enough for my use. The bigger alternator does a magnificent job of bring the battery back to full charge after the starting load. By the time I'm out of the garage the voltmeter is up to 13-point-something. Why MB didn't put something larger in their diesels of that era is beyond me.

I'm with you on that. Who in their right mind sent a can bus W210 out the door with a 90a alternator? Especially one with afterglow which can run for up to 3 minutes. If I used the car for short trips around town it would stay below 12v for minutes at a time. The low voltage would cause the 722.6 shift hard and sometimes not at all. With the 150a alternator its at 13v+ instantly after start up even while the glow plugs are still on.

So far I have:
Seat modules
Alarm
Rear vacuum pump
To check. I'll give it a shot friday night if I have time. Thanks to everyone for your contributions.

jay_bob · #19 12-16-2015, 03:52 PM

I am going to have to put the CCU on diag mode parameter 24 and see if my voltage drops off like that next time I'm in the car.

I did the upgrade on the 87 wagon with a bigger alternator (and the wire harness) from a mid 90s gas 124 and wow what a difference. Actually my younger son who drives the car did the work. Went with me to the JY and then installed it. I just coached him and handed him tools. He is about to graduate HS and is looking at mechanical engineering.

tjts1 · #20 12-16-2015, 06:17 PM

I think most 98s got a 115a alternator from the factory if I'm not mistaken.

tjts1 · #21 06-15-2016, 02:32 PM

It was the cabin blower fan controller. I replaced it last week after realizing the top 3 speeds weren't working and no more battery drain after that.

engatwork · #22 06-15-2016, 08:14 PM

Thanks for posting follow up. I know on some applications when the fan went out you had to replace it and the fan controller to an "upgraded" unit.

tjts1 · #23 06-15-2016, 10:34 PM

Quote:

Originally Posted by engatwork

Thanks for posting follow up. I know on some applications when the fan went out you had to replace it and the fan controller to an "upgraded" unit.

Yeah, the early W210 up to 99 had a very high fan controller failure rate, they completely redesigned the controller and fan and that was the only option for a while to the tune of $1000 from the dealer. Then some smart mechanic figured out that the W140 fan controller bolts up and works in the W210 with a bit of splicing. More recently the aftermarket stepped in and you can pick up either a W140 or W210 fan controller on ebay for ~$20. I bought both, tried both and settled on a W210 unit which was plug and play.

Since I wasn't able to figure out the source of the battery drain for a long time and I only really use this car on the weekend, I got in the habit of plugging it into the charger every wed for a few hours. Normally after its been sitting for 3 or 4 days the needle on the charger shows about 50% initial charger. Today when I plugged it in it showed 100%. It took me a moment to put 2 and 2 together and it dawned on me that I replaced the fan controller last week. Go figure.

jay_bob · #24 06-18-2016, 06:36 AM

Yep that fan controller red wire is connected directly to the main unswitched dc + terminal with no fuse.

Yes that is right, no fuse. Guess they were sick of hearing about melted fuse holders from the 123/124/126 and thought "we'll show them..."

I do not know how they got away with that...I sure could not in my products...

tjts1 · #25 06-18-2016, 03:02 PM

On the plus side, the w210 fan controller can be changed out in about 15 minutes from underneath the dash so is an easy swap. The W140 controller seems to make the fan blow much harder. Would make an excellent hair drier. But I don't feel comfortable using it without its own dedicated heat sink.

tjts1 · #26 06-18-2016, 03:09 PM

Quote:

Originally Posted by jay_bob

Yep that fan controller red wire is connected directly to the main unswitched dc + terminal with no fuse.

Yes that is right, no fuse. Guess they were sick of hearing about melted fuse holders from the 123/124/126 and thought "we'll show them..."

I do not know how they got away with that...I sure could not in my products...

On the plus side, the w210 fan controller can be swapped out in about 20 minutes from underneath the dash. The w140 controller makes the w210 fan into an excellent hair dried. But I didn't feel comfortable with the w140 controller in there without its own dedicated heat sink. I might cobble something together later. Fow now I'm happy with the output from the 210 controller.