Last Monday I drove Mrs Squirrel and me to the airport. It was at 5 am,
plenty dark, and I noticed that the dash and headlights were brightening
and dimming, just perceptively, and very regularly, with a period of
slightly over a second

We returned from the airport last night, in the dark, and I noticed the
same thing. Just enough of a voltage variation to cause the lights to
dim and brighten to be noticed.

I first thought it was in sync with the second hand on the clock (84,
1.9L) but they drifted apart after about ten seconds -- so it has a
period of about 1.1 seconds and it is very regular.

I have a voltmeter shoved into the cigar lighter socket but it's of the
digital variety and is useless for tracking brief events like this.

I no blinkers were on that would have sucked power on a cyclical basis.

I may have to get an analog meter and connect it to various bits in the
van to find where the voltage swing is highest. Anyone got a working
Simpson 280?

Before I dig deeper into this, can anyone tell me if this sounds like an
alternator voltage regulator thing? It does not vary with engine rpm.

--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
Bend, OR
KG6RCR