I have a 97 C230 with 153,000 miles. Recently the charging indicator light has started to illuminate very dimly and the battery is discharged and I have tp put it on the battery charger. I'm curious why the light is so dimly lit to indicate a problem. The battery takes a good charge and will hold charge unless the car is driven. The battery is the ORIGINAL from 97 so I assume that it is defective but still wonder why the indicator light does not illiminate properly. It is so dimly lit in daylight you can't even tell it's on.

Thanks in advance as always...

 

alternator possibly

 

check if your battery increases the above 12V when car is running using Voltmeter. May be Autozone or your local auto parts store will do this free for you. If you are not gettting more that 12V, it is Alternator. Most of the time, actual alternator is not a issue. Regulator inside voltmeter is bad. Changing Regulator will be much easier and cheaper than changing entire alternator. There are Youtube video on how to change regulator.

I had similar issue and i ended up changing entire alternator since I had diff. brand that BOSCH in my 1999 C230 car but if you have BOSCH Alternator, regulator for BOSCH is much cheaper than actual alternator since it is easily available in market.