IOW, it does most of what I need to keep a D-jet running!

I've browsed some of the archival stuff on the D-jet controller. I remember the critical element being the MAP sensor, and being very impressed by the effort put into restoring and maintaining the system. The design of it was breaking news, too, in automotive circles.

If I was to hazard a guess, I'd picture a Simpson 260. You're right. Used in the manner I suggested, you'd be splitting hairs on the scale unless you could stretch the probes to measure actual drop between source and load, on its 1V scale. That's where a DVM's eye-saving resolution helps - you can conveniently avoid the stretching. And when I chose those loads for testing examples, I was thinking distant loads, but the alternator is still up front on the motor, I suppose.

My daughter's '02 BMW has the battery in the trunk, and a post, like you describe, under the hood for jump starting. Just a couple weeks ago, I learned it must use that load switching, copper-saving, car area network approach when I noticed her tail lights flickered. Barely perceptible, until compared with steady, full on brake lights.

Those tail lights had the same 21W bulbs as the brake, turn, and backup lights, but were mimicking 5W lamps by being switched on and off at a rapid rate, just like the frequency valve on a k-jet lambda car. That was the flicker I noticed. My DVM wasn't much good at perceiving it either, but an analog meter would see the average, and the oscilloscope I found even more handy (my Simpson's red test lead dry rotted) proved the pulse-width scheme.

It must have been a painful compromise in the quest to reduce weight and expense of copper wire only to run a heavy cable from trunk to engine for cranking.
--
Art Benstein near Baltimore

BTW, don't buy the $25 DVM Walmart sells as "Innova Autoranging." It can't be taken out of that mode.