Get well soon Ed..
replaced the alternator, and found out the 2004 model year had two different alternators.. the first one I ordered didn't fit. Returned that for a refund, and took the old one down to the local auto parts place to make sure I got a physical match. Most of the local places have kids behind the desk, but there's an O'Reillys with a couple reliable old guys working there. They were able to find me an alternator that fit.
Problem was sporadic hiccups at idle - battery light came on briefly, engine almost but not quite stalls. On my last 3 cars the only times we've been stranded was with alternator problems, more accurately voltage regulator problems. The Sienna cut out while climbing Vail Pass at 65mph in the fast lane, passing trucks in a blizzard. I thought we were all going to die. Survived that luckily. The Subaru Outback cut out on the way to church once but restarted. The second time it cut out I ended up replacing the alternator in a Walgreens parking lot. The MDX gave up on the way to Minnesota, leaving my wife and son stranded in North Platte NE. That ended up costing nearly $1000, the OEM MDX alternator is over 400 plus labor. I coulda done it at home for under 400.. oh well.
So I have alternator scars, and knowing this was the original alternator I figured it wouldn't hurt to replace it, the serpentine belt and tensioner. If the hiccup shows up again it isn't the alternator at least.