Another thread and another car to take a break from some FPR/OVP issues I have with another 300E I drive that some of you were good enough to try and steer me through. That still unresolved issue I had to leave for a while rather than shoot the bug*er.

That said, I'm onto car number two and first order of business was removing the alternator which isn't charging a good battery and is only according to the seller a year old. The car has 190K stored indoors most of the time. Wiring is mint and barely any rust anywhere.

Car starts great with a boost - red charging light always on. Good battery which eventually drains since there's no charge coming back. Alternator
turns fine, no noise, bearings are good but it isn't producing any juice.

Hoping once I fix it will go back in easy. Assume the worst will be getting the belt back on the pulley. I'm going at all this w/o a manual but lots of domestic car experience and I know there's a tensioner to loosen but I couldn't find it or how to access with fan blades, shroud and rad in place.

Questions. Reading through some old threads I've seen some discussion about repairing the alternator myself. They're going to ding me for $100 plus minimum to rebuild, closer to $200 for a rebuild from a autoparts dealer. If I can save that by doing what is suggested in other threads that would be great. Being that it is only a year old, I can't figure out why it isn't generating. Saw an article that mentioned a VR/brushes cleanup that might be the problem? It's a 'valeo' regulator which looks new. Based on my alternator knowhow I wasn't aware a VR could be what makes an alternator fail. Thought a VR only handled the charge once an alternator produced a charge as opposed to being the cause for no charge at all.

But the nut on the negative (small) terminal bolt of the alternator is impossible to loosen. I ended up snipping the wire close which is easy to solder a terminal end back onto once repaired and getting a good crack at it off the car seems to make sense. I soaked it with penetrating oil but it is on tight enough to spin the bolt it's frozen onto and since there's nothing to grab to stop the bolt from spinning I'm wondering how to get it off. There is a nut below the seized nut and terminal end but it's buried too deep to grab with anything, there's no way to jam it from turning since the black plastic insulator that surrounds the bolt would break trying to jam anything in the keep it from turning. It's on so tight I'm thinking it must have 'cooked' itself on - that may be the problem.

That alone may spell rebuilder. If that terminal bolt spins around is it not breaking the contact or wire it's attached to inside?