CLK 500 - alterator?

[h8tax]

I have just picked up my new (to me) car - a 2002 CLK 500, with just 21k on the clock and full MBSH. Its lovely, but, I discovered it had a knacked battery, which I replaced today. After installing, checked all the voltages and it was charging just fine with the engine running.

After clearing the leftover assorted error codes from the battery swap, my battery voltage warning has come back on and the alternator is no longer charging with the engine running.

Is there some kind of voltage sensor that controls the charging, or do I just have a knackered alternator?

[JimmyR1]

Probably just the voltage regulator. I am not certain for your model MB but on typical alternators it is replaceable and easy to access without having to remove the alternator. It might still be worth quickly checking the cost of a reconditioned (or OEM) alternator as well. Labour would be about the same so it might make sense (and give you peace of mind) to replace the whole unit??

[h8tax]

Thanks for that - I will investigate - although the 5l engine makes access a bit tight in there!