Fusible Link in charging circuit?

[gregs210]

Hey, folks.

Long story short, the battery/alternator visit workshop message came on while my niece was driving the other day. She said there was no noise or smell or anything. The car is a 2001 W210 (E320) and I'm given to understand there is a great deal of commonality shared with a couple of other platforms as regards the alternator/charging circuitry.

Car started fine, normal cranking sound/revs etc. As I drove home the battery was clearly dying. I replaced the battery about 6-8 weeks ago as a preventative measure, given that it spun the engine just fine and slowly discharged I doubt seriously it's the battery.

I already searched for my question, so I know it's not already answered.

I'm a big DIY guy, and in the domestics I used to own with those symptoms I'd simply replace the alternator. However, on another forum I saw mention of a fusible link (no specifics, of course), and I'd rather not spend a few hundred dollars on an alternator if it's not the problem. I asked a mechanic who supposedly specializes in MB products, he kind of wrinkled his brow and said, "I don't think there's a fusible link, there is a fuse, however." He indicated it was in one of the blocks, not inline. So I inspected my fuse list, couldn't find anything on it that suggested anything related to the charging system. Being a methodical sort, I then proceeded to pull and inspect every fuse in all three locations. All of them are good. So it's clearly not a fuse.

So, folks, if any of you have any *specific* information as to (1) whether there is a fusible link in the charging circuit and (2) where it might be located, can I trouble you to post up and give me some feedback and details? Once you know where it is testing a fusible link is simple, much easier than testing an alternator.

[Additional generic info: While my model year was included in the charging system recall, my specific chassis serial number excludes my car. Also, some folks have opined that it's usually the voltage regulator, which is a $30 part, obviously I don't want to buy an alternator if I can just swap the regulator, even though it means removing the alternator to swap it. Are there folks here who have some meaningful input on the regulator issue? And yes, now that the battery has been recharged I could take it to have it tested, but (1) the estimate for the diagnosis is around $100 and (2) then I have to drive it back home and fix it anyway, and then the battery will be low again.]

Your meaningful input is much appreciated.

Take care and enjoy the ride,
Greg