Stranded, need quick advise - PeachParts Mercedes-Benz Forum

fahrgewehr2 · #1 05-09-2004, 11:37 AM

On the way home late last night, in my SE, the ABS light comes on. Shortly after, the SRS light comes on and the radio begins to turn off. Lights are very dim so I pull off the road.

I stop the car and try to restart- no enough juice. I waited about 15 minutes and tried to restart- fired up, but still not enough juice to run everything- and abs/srs lights come on after idling for a few minutes.

I will search the archives in a second, but if someone can nail this, it would make my day.

Oh yes- the BATTERY idiot light is NOT lighting up when car is running.

Mike

Evan · #2 05-09-2004, 11:45 AM

I would be willing to bet money it is your Voltage Regulator in the back of your alternator.... When the two brushes wear beyond a point of bad contact they no longer charge the battery,,They are about $40.... Be careful when you unscrew the old regulator,, the screws often brake or strip.. treat it with care.... attached is a picture of the culprit..

fahrgewehr2 · #3 05-09-2004, 12:04 PM

Yes, that was the part I was thinking of. Thanks for the picture.

Looks like the car will have to wait until tomorrow as no one is open today.

Maybe I will pull the VR off of my parts car to try.

I will post my conclusion for the sake of the archives.

Mike

stevebfl · #4 05-09-2004, 12:08 PM

The regulator is a good possibility but usually when the brushes are the problem the light will come on.

The ABS will quit if there is no charging for any reason as it uses the alternator to know the engine is running.

Evan · #5 05-09-2004, 12:11 PM

Well a common problem with the voltage regulator is, when it wears down to a certain point, it doesnt usually make enough contact to charge the battery, however it does make just enough contact to keep that light on,, it has been a flaw in design

fahrgewehr2 · #6 05-09-2004, 12:58 PM

Alternator is about 5 years old. Battery is probably at least 6 YsO.

I have two possible plans-

Leave the car where it is and come back tomorrow with a VR and whatever other parts may be causing the problem.

I am thinking driving home is a bad idea, as I need to cross the (Chesapeake) Bay Bridge, and if the car is going to die, we all know it will be on the middle of that bridge.

The car never died last night, so there may be hope for a limp home?

Evan · #7 05-09-2004, 01:01 PM

Easy way to do it is just remove the VR and inspect it.. if the brushes are very worn, then you know what your problem is..

haasman · #8 05-09-2004, 03:04 PM

Mike

The obvious question: The belt is tight?

A six year-old battery in my experience is getting pretty old. It may simply mean a new battery.

Keep us posted,

Haasman

ohiomike · #9 05-09-2004, 07:53 PM

YEP...HAD SAME PROBLEM ON ONE OF MY 300SE's...IT WAS THE VOLTAGE REGULATOR...CHEAP FIX AND DIY.

fahrgewehr2 · #10 05-09-2004, 11:38 PM

Belt is tight and turn the alt. as it always has. I don't think it is the battery as I can watch the voltage drop while the car is running.

Car OFF- 11.8V
Car RUNNING- 11.4, dropped to 11.2 over 15 minutes.

Needed a short shaft philips head to remove the regulator. Will head back to the western shore and try to get her going tomorrow.

Mike

stevebfl · #11 05-10-2004, 08:15 AM

Take a charged battery and put it in the car and drive it home. If you leave the lights off and the AC w/blower off you can drive nearly a tank of gas out on just the battery.

The ABS will be inoperative during that time.

fahrgewehr2 · #12 05-10-2004, 08:37 PM

Voltage regulator fixed the problem. The old one was worn down about 95%- nothing left.

Of course two other (unrelated) problems popped up on the way home, which makes me pretty unhappy.

Thanks for the advise guys.

Mike