I finally upgraded the alternator.
I found a used Wrangler NW 155A alternator (10K miles on it) second hand on craigslist.
the price was right.
Fitment was ok. it's a modified Delco alternator and has an addiitonal arm to attach to the stock mercedes mounting. I think it could have been better designed but it's solid once installed.
The pulley is about 1/8" too far forward and the grooves don't match the MB 10mm wide belts very well. The result is a loud whirring from the belts and a subtle burned rubber smell. The wiring however, is top notch.
I'm carrying an extra set of belts and was able to get a new pulley from a local shop that should fix the alignment problems. I'm hoping to get some time tomorrow to swap pulleys.
BTW, the military clamps on the batteries are great - since all the cables use the same 3/8" lug, it's easy to reconfigure everything without having to rebuild anything. just unbolt from one clamp and bolt to another.
I think that if there's ever a problem in the field, it will be easy to adapt a new circuit layout based on the parts that are there.
- wrangler northwest alternator installed
- wrangler alternator wiring to batteries