[Grandma’s 68]

I can see the logic that the alternator wired to the starter post that is connected to the battery basically ‘shorts’ out the rest of the power circuit. It’s all still live and current flows to the devices but not much to cause a differential over the ammeter. Basically negligible flow across the ammeter, so not moving.

I tried a quick test by cutting the alternator wire at the starter and jumping it to the ‘correct’ location at the b/w fuse.

However it doesn’t look like I’ve got any change in ammeter results. I get about 0.17A between black and b/w wires. That about the same as before (0.22A). Now that may be coincidence, so is it normal operation of the gauge basically sitting in the middle with a fully charged battery and functioning alternator? Is 0.2A flow what to expect?

I also noticed that the ‘shunt’ wire that goes along the front of the truck looks a heavier gauge. Is the ‘shunt’ wire some sort of special wire?

I may still rehash the wiring to get it like the original diagram, but I’m curious now to functionally test the gauge and would appreciate some guidance on how it’s supposed to look under normal charging and how to simulate alternator failure.

Thanks.