Shut off and now will not stay running

ALEX90945

MEMBER
2000 MERCEDES BENZ C280
AUTOMATIC
200,000 MILES

Hello. So I had noticed a few times that my car's lights and electrical functions began to dim and work weaker (e.G, the windows would move slowly). Then one day it only lasted about 20 seconds on and then it shut off, and now it doesn't turn on anymore. With the help of someone who knows something about cars, it seems we were able to deduce that the alternator was the cause of the problem. We jump started it but it still shut off so, which seemingly implies it is the alternator. However, I would like to know if there are other possible causes. Also, I do plan to replace the alternator but what tools would I need and what process would I follow? Do I need to remove the belt in front first? It has oddly shaped screws that I can't take out with my current tools.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Hi,

Here is what I recommend trying. We need to confirm that the alternator is truly bad or if it is something different such as the battery itself.

I would first fully charge the battery. If it is something you can't do at home, most parts stores will do it free of charge. At that time, have the battery load tested to confirm it is good.

If it's good, then check for alternator output. It only requires a volt meter or a multimeter. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If the alternator fails, here is a link that shows in general how one is replaced:

https://www.2carpros.com/articles/how-to-replace-an-alternator

Here are the directions specific to your vehicle. You will need general tools; however, a reverse torx socket is needed to do this job. These are what the bolts holding the alternator requires. It is important that the battery is disconnected before you start working on it. The attached pic correlates with these directions. And yes, the belt will need removed before the alternator can be replaced.

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2000 Mercedes Benz C 280 (202.029) V6-2.8L (112.920)
AR15.40-P-5032EB Remove/Install Generator
Vehicle Starting and Charging Charging System Alternator Service and Repair Removal and Replacement AR15.40-P-5032EB Remove/Install Generator
AR15.40-P-5032EB REMOVE/INSTALL GENERATOR
Remove And Install Generator

Shown On Engine 112

Pic 1

1 Disconnect battery ground line

NOTE: Insulate cable lug of ground line for protection against unintentional contact of disconnected ground line.

2 Remove bottom engine compartment panel
3 Remove ribbed V-belt
4 Disconnect electrical line circuit 30 (B+) (1) and electrical line circuit 61 (D+) (2)

Nut, terminal B+ to generator - 18 N.m
Nut on alternator terminal D+ - 5 N.m

5 Unscrew alternator screws (3)

Bolt of generator - 42 N.m

6 Remove alternator (G2) downwards
7 Install in reverse sequence.

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As far as belt removal, there is a tensioner that you will need to turn counter clockwise to release tension. I highlighted the component in pic 2.

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Let me know if this helps or if you have other questions.

Take care,
Joe

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