This happened to me on a 90 Carat, with a surge period of about half a
second. Replacing the alternator was the solution.

Jim

On Fri, May 21, 2010 at 10:36 AM, Mike "Rocket J Squirrel" <
camping.elliott@gmail.com> wrote:

> 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
>