Charging system woes..... - PeachParts Mercedes-Benz Forum

Biggg Willy · #1 12-10-2005, 09:34 PM

I had a very similar problem.

Another symptom of mine was when I had my key is postion 2, only half of my warning lights would come on (the ones in the bottom of my gauge cluster).

The cause? The brushes/regulator unit. It takes two seconds to take out, you don't even need to jack up the car (if you're skinny, and can shimmy). Its on the back of the alternator, you just need a phillips screw driver to take it out (but a phillips socket on a 3/8ths rachet would be better - it'll probably be pretty stuck). Take it out, examin it, clean it, then try it again... If it still doesn't work, replace it. If its still the origninal alt. then it'll need to be replaced soon anyway. Its only a 20 or so dollar part, so no big deal if its not it, at least you've worked it out of the system. Its probably the cheapest common failure on these car$.

If you're lazy like me, doing this is much easier than checking all your connections

.

deerefanatic · #2 12-11-2005, 06:07 PM

I took the voltage reg off tonight. very easy, even from the top of the car. It was very greasy and grimy. The brushes had a lot of life left on them. I used carb cleaner to clean as much gunk off as possible. Put it back on, no change.

I am pretty certain that the alt is working partially though, as the battery light is dimmer when engine is running than when it isn't running but key is on. This leads me to believe that some juice is coming out.

The current voltage reg is a Bosch unit, so I am assuming that it is original. (Due to the PO's track record...)

I will try and check voltages with my DMM with car off, on, on w/ accesories, etc.

Would autozone, napa, advance auto, etc have this part? I don't really want to be without my car for nearly a week waiting for shipping, and can't afford overnight.

JamesDean · #3 12-11-2005, 07:45 PM

this is what they list for that part

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=GPS&mfrpartnumber=265019&parttype=204&ptset=A

i dont think that looks like this thou:

https://www.***************/secure/PartImages/1197311028.jpg

but i doubt they actually have it in stock. they would have to order from another store...

Hatterasguy · #4 12-11-2005, 07:50 PM

MB actually puts a warning in their manual about not running all 4 seat heaters, defroster, climate control, lights, radio, and adjust the seats at idle. If you do so you will draw more juice then the alt puts out. So basicly don't have all your friends play with all the cool stuff in your 560SEL as it idles in the driveway.

Your alt is probably getting weak, I'd have it load tested. Don't ignore it or you will be walking, I'd sudjest carrying a set of jumper cables with you.

boneheaddoctor · #5 12-11-2005, 07:53 PM

Quote:

Originally Posted by deerefanatic

I took the voltage reg off tonight. very easy, even from the top of the car. It was very greasy and grimy. The brushes had a lot of life left on them. I used carb cleaner to clean as much gunk off as possible. Put it back on, no change.

I am pretty certain that the alt is working partially though, as the battery light is dimmer when engine is running than when it isn't running but key is on. This leads me to believe that some juice is coming out.

The current voltage reg is a Bosch unit, so I am assuming that it is original. (Due to the PO's track record...)

I will try and check voltages with my DMM with car off, on, on w/ accesories, etc.

Would autozone, napa, advance auto, etc have this part? I don't really want to be without my car for nearly a week waiting for shipping, and can't afford overnight.

can you hook up a voltmeter and watch it while driving over a period of time...like I said they can become intermittant even with plenty of brush life....

deerefanatic · #6 12-12-2005, 08:45 PM

I hooked up a DMM tonight (straight to battery). Battery voltage sags during cranking, but doesn't come back up past 12.2 volt after start. It will sag if any device is turned on.

Leads me to believe that the alt isn't puttin out a blessed thing.

I am going to see if the shop my dad has the tractor starters fixed at can do a quick check over, maybe they have the part in stock.

Dervman · #7 12-13-2005, 10:23 AM

Sounds like the Diode Pack/Voltage Regulator is dead.
I replaced mine last year with an original Bosch part from a Bosch dealer.
It includes the whole assembly with brushes and everything.
I think I paid about $50.

dannym · #8 12-13-2005, 11:20 AM

Quote:

Would autozone, napa, advance auto, etc have this part? I don't really want to be without my car for nearly a week waiting for shipping, and can't afford overnight.

ShopForum ships faster than anyone. usually in 2 days. You may pay more $$$ but you get quality and you get it fast.

Danny

deerefanatic · #9 12-13-2005, 12:01 PM

You'd get your part in 2 days from *************** too! You live in Florida, and both Fastlane and BuyMBParts have warehouses in Florida.

I am in Michigan! Slightly different posistion on earth!