Yeah, I don't know, but driving around like on the highway, after awhile, the dash and headlights dim and brighten in a very stochastic fashion. Just dim, then bright, then dim and so forth. But dim seems OK. So along with Math, Electronics tends to be mysterious. Any thoughts are welcome. El Camino Central is the Best. BTW, the engine just hums even, even while that is going on.
J

My '74 Sprint did the same thing, then it died and would not start. It wouldn't even turn over. I'd turn the key, and nothing. When I got a jump, it fired right up, and then died again on the way home. The following morning, it fired right up again, then died within 2 minutes. Now it won't start again. When I popped the hood, I found that the positive battery terminal (can't find the battery hold-down) was bumping up against the little metal tube from the top of the radiator and sparking the battery and draining it. I assume that's the only problem, but I'm taking it to the shop next week to make sure.

...after awhile, the dash and headlights dim and brighten in a very stochastic fashion. Just dim, then bright, then dim and so forth.

If the engine is unaffected I'd guess it's isolated to your headlight circuit. I would even venture a guess and say possibly the headlight switch is bad or the connector for the headlight switch is loose. Do you have a voltmeter in your Elky? If so, what is the alternator voltage doing when this phenomena happens.