Help Needed Almost An Accident - PeachParts Mercedes-Benz Forum

benzman2 · #1 12-20-2006, 05:08 PM

Hi,

I was at a gas station today and when i got back in the car to start it up it would not turn over. The battery was in good shape but I feel the alternator has had it. After a jump start I managed to drive the 30 miles home but during the way I lost power in the windows, radio, and the tachometer to name a few finally right around the corner from my house the car died and due to no power in the steering I almost smashed another car.

My question is, is it the alternator for sure or could it be something else i dont know?

Thanks

Gilly · #2 12-20-2006, 05:19 PM

My bet would be the alternator, yes. If just the battery craps out, a jump start will get the engine started and then the alternator should keep you going all by itself. Although the battery can fail in such a way that the alternator is ineffective, I think this type of failure is referred to as a shorted battery or shorted plates. But I guess it's rare that they fail in this manner, but it's possible. If you can give the approximate age of the battery it would help. Also you should be listing which car you have, but I looked at your other posts and found it's a CLK320?? Could list this in your profile, that would make it easier too.
Gilly

manny · #3 12-20-2006, 05:21 PM

Sounds like an alternator/regulator problem.
The reason you got 30 miles out of the jump-start proves, that your alternator was NOT charging the battery.
You only drove on " borrowed " ( from the boost ) time.
Remember, anything below @ 10 volts & ALL automotive electrical systems shut down.

Tomguy · #4 12-20-2006, 05:23 PM

Sounds like it. Could be a voltage regulator though. What kind of car is this?

benzman2 · #5 12-20-2006, 08:07 PM

Sorry guys.

Its a 1987 300E. The CLK320 is my wifes car.

Thanks

865sp300e · #6 12-21-2006, 09:10 AM

The same exact thing happened to me with my 1986 300E. It was the voltage regulator which is a quick, inexpensive, and easy fix. Do a search for details.

david s poole · #7 12-21-2006, 09:56 AM

true it can be the voltage regulator[brushes worn down to zip]but the smart thing is to replace the alternator with bosch rebuilt because the shaft that the brushes ride on is also worn.

xan021 · #8 12-21-2006, 01:34 PM

With the engine running disconnect the battery. If the motor shuts off the alternator is bad, if it keeps running it is good.
That's how I always tested alternators without having to take it off the car and drag it to an auto parts store to have them test it.

Tomguy · #9 12-21-2006, 04:04 PM

Quote:

Originally Posted by xan021

With the engine running disconnect the battery. If the motor shuts off the alternator is bad, if it keeps running it is good.
That's how I always tested alternators without having to take it off the car and drag it to an auto parts store to have them test it.

The car will also stall if the voltage regulator is bad.