2008 C300 Sport owner here.

Had a look underneath the car yesterday, the fastener (the red arrow) seems to be in a very tight spot. I think that will be the #1 challenge. But let's say I somehow manage to loosen it, I will have a few more fasteners on the regulator itself to worry...again with very tight spot. #2 challenge.

Is this doable without taking the alternator off completely? I can't see myself doing the entire job so I am hoping it's the regulator's fault and hope not have to take the entire unit off.

 

What problem are you trying to solve? I just had my alternator replaced to cure what I thought was an abnormal whine. Turns out it's a normal whine.

 

Red battery light on speedometer.

Battery replaced, the light still comes on.

Btw, did you pay someone to do it? I can't see myself performing a difficult "preventive" maintenance such as the alternator unless it fails.

 

Yes I paid someone but brought my own alternator. It was 2 hours labor which worked out to about 250 usd

 

Anyone else may have done this without taking the alternator off?