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:
If the alternator fails, here is a link that shows in general how one is replaced:
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.
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
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.
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.
Let me know if this helps or if you have other questions.
Images (Click to enlarge)
Saturday, October 17th, 2020 AT 9:24 PM