E300TD Battery/Charge message
so you have good voltage at rest...good while car is running.
what made you decide to get a new battery? if you still have it, can you swap them out to see if the warning indication reappears?
what is the battery voltage while it is cranking (under load)? I can't remember if this may provide an indication of a dead cell. it shouldn't as i is new. the 12.6 tells me it hasn't sulfated
new alternator: is it a MB replacement or a comparable (eh, that'll do) part ? I believe that a poorly matched diode me send a signal mimicking an error when this isn't the case. I drove a truck with a mismatched diode for 15 yrs after the alternator was replaced. I ignored the charge light on my Nissan all that time (since it was only a soft, barely there, glow).
The previous battery was old and would not hold a charge. The new battery was installed in June 2017. That is when a plethora of problems started.
The alternator is a reman Bosch
Thank you all for your input




8.8V cranking is low again, but if you don't have load tester, turn all the lights and blower on and check the voltage in the lighter socket and then on battery. Engine off. Comparing battery prongs to clamps will show potential dirt.
Trending Topics
I am very apprehensive to disconnect the battery at all as this created several problems including but not limited to ruining the Aux Fan Controller that is located up inside the front bumper. Also had Check Engine light which was cleared.
Thanks again!
The Best of Mercedes & AMG
Your car likely has a disconnect for the negative cable on the heel kick in front of the battery. In my '97 all I lose is the radio when I disconnect the battery. You can keep everything alive with a 9volt battery and alligator clips, before you disconnect, but it is about as easy to just use your radio code. The relay problem was almost certainly unrelated.
Get a proper terminal brush before you start. They are cheap and do a great job quickly.




On 1998 and newer models beside radio code you need to synchronize steering sensors, windows and sunroof, but last 2 can be done during driving, so I never spend more than 1 minute on parking after battery reconnect.
Last edited by kajtek1; Nov 23, 2017 at 06:00 PM.
The most recent problem was the original horn stopped working so I removed it and bench tested it. It was barely buzzing. Replaced with a new horn but still didnt work. I looked on the fuse location card but found nothing that stated "horn". Upon searching through several posts in online blogs I found that it is fuse #40 defined FANFARE. The fuse was blown, replaced with same amp fuse and horn is fixed.




