morechunch

Also, I want to advocate for the shop I took it to.  It's a two man operation, normally they work on Jaguars and Porsches, talked to the guy who did the work about the DMV and his Ducati when I picked it up, but they were very happy to take on my alternator change before that.  No overnight lot fee and about 5 hours worked for $240.  They even re-fitted a plug that didn't fit right on my replacement alternator and plugged up and gave me the old one back, without me asking.  Believe me when I say, this is a very charming van.  It got me, it got my friends, it got my dad, and now it's got a high performance shop. As silly as it sounds, we're all droolin over a super clean Mitsubishi van here in the middle of the US.

Sounds like brushes are worn in alternator. Or maybe blown rectifier.
What is battery voltage when idling?
What is battery voltage when at say 2000rpm?
Turn all the electric things on- fans, lights, demister, wipers, and what is voltage at 2000rpm?

Alternator is finally successfully replaced, voltage at idle is 12.4 - 12.7; pretty low but not deadly.  At ~2k rpm it's around 14 like it should be.

Took it to an import shop, the guy was awesome and seemed like he was just happy to see something new.  When I told him the oil filter was overtorqued before I brought it in, he believed me after working on it.  Great dude, he worked hard to get it off without damage and gave me some suggestions on where to source a new one.  My closest is Latvia, he thinks some old Volkswagen might work.  He put in extra effort to get the connections the battery on clean, but I do wonder about the grounding,

There's a plug fuse-box on the positive cable, but the plugs warm up fine.  I can check the fuse tomorrow.

All electrical is also good, there are some strange things done to the wiring through the van though.  The front in-door speakers are just gone, and the front overhead, I don't know, reading lights is what I've always known them as, has been pulled out.  It came from a Japanese shrine originally, I wonder if somebody wanted to install a PA system?  Treat it like a taxi or tour bus?  Something was done wrong to this poor van, and I aim to rectify that.

It's been a drag.  I am in the US, so it's not something I can go to the junkyard for.  But your suggestion of just replacing the pulley sounds reasonable, the motor isn't bad.  As long as the pulley works and is clipped and crimped with the right lengths, any pully should work.

I have a shop ready to work on it.  Drove the 20 miles round trip to get the inspection done, inspector called me out of the driver's seat to just talk about the engine, he was excited.  Looking at Honda Civics all day probably does that to a guy, I was happy to get out and talk to him.  Battery after round trip was down to 62% and 12.4 V.  Around 45 miniutes total on the mean streets, with a second no-jump startup and no electical failures.  Maybe it is just a bad belt. But I won't have a guy who actually knows what he's doing look at it til next week.  

I took my RVR over to the parents' as I promised, and trickle charged the battery there.  My dad pointed out something interesting.  He doesn't think the terminal clamps were chewed up by tools, he thinks they exploded from reverse polarity.  He doesn't think I could have made it there if the alternator was failing 100% of the time.  He pointed out a huge doming gouge on the negative side that he doesn't think a tool would do, and the rest of the damage is all little domes everywhere, if that makes sense.  I still need a new alternator belt (have one) and still have to figure out how to install that, but his suggestion was to get those cables/clamps changed and see what the alternator does. 

EDIT: Stores are closed for the holiday, and I'm gonna be swamped at work tomorrow over it.  Doesn't change the over torque situation with everything from the oil filter to the lug nuts that I broke off and retightened, but it's a fix that needs done and might as well start with.