'87 4kq: temporary no-juice condition

[Andrew Buc]

I was on an errand a couple of miles from home today, and suddenly the
windshield wipers began running much slower than their normal speed. And then
the car started losing power for maybe 5 or 10 seconds, and I noticed that the
digital voltmeter was at the bottom of its scale (8V). I shut off all lights
and accessories and headed for home. The car began running OK again, but the
voltmeter stayed at 8V.

I got home, and after maybe a minute, the voltmeter came back up to ~12V. I
tried the wipers, and they ran fine. That was all a few hours ago. I just went
out and tried starting the car (no problem there), and the voltmeter was at
~14V. I don't remember the alternator light coming on earlier. I can't rule out
the possibility that it came on and I missed it because I was concentrating on
the other things going on, but I'd think it would be pretty hard to miss.

I took a Google walk thru the archives, and I gather that worn brushes can
often account for alternator problems. I'm not about to get under the car today
(cold and rainy in Seattle), but w/174K on the car, I imagine worn brushes are
plausible. Or do the symptoms point elsewhere? The way the problem came and
went for no apparent reason doesn't leave me confident about driving the car
right now! Thank you.