Finally got around to doing the bulkhead bypass I mentioned I was gonna do earlier. Used a step drill bit and drilled two 8mm holes just under the bulkhead connector, spot painted it with some black spray paint to prevent rust, before sticking a grommet in each hole. Kinda shitty pic; took it at night and it was raining lol. You can see the red and black 10 gauge wires I added in the bottom left corner of the pic. Red goes to alternator, black to battery. I should've swapped the cable colours around...oh well.
Removed and taped off the stock eye terminal on the back of the alternator, then taped off the eye terminal of the battery wire going to the red stud on the ammeter. As mentioned, unfortunately, I forgot about the whole red stud on the back of the ammeter thing, so now the black wire has to go to the red stud and vice versa lol. But it all works. Screwed down the factory black wire on the black stud, together with the new wires, so now the factory power feed pins on the bulkhead are completely bypasssed while the ammeter still works as intended.
Waiting for paint to dry is annoying...I think I'm going to buy a bottle of nail polish top coat. Stuff is great for protecting interior plastic buttons from rubbing off, might serve me well in coating exposed steel.
Update: re-reading the MAD article again...as far as I can tell, it matches what 72RoadRunner is saying - to bypass the bulkhead connector packard terminals, it even says those are the weakest link in the whole system. It mentions the primary reason for bypassing the ammeter is because the gauge "often fails" and "sometimes it burns dashes." So it's basically just trying to eliminate a potential fire hazard inside the cabin. A point of contention could be made if the passenger car ammeter internals are beefier than people realise however, in which case, the stock ammeter can be included in the new circuit, and when used in conjunction with one of those little cigarette lighter voltmeters, can give you more information about the electrical system. The article makes no mention about proper load placement however, which is probably where people start having problems.
So basically...
- bulkhead connector sucks, bypass the power feed terminals with 12 gauge wire at an absolute minimum, larger if futureproofing/adding more electrical stuff
- passenger mopar ammeters are beefier than people give them credit for
- additional loads should be placed on the wire between the alternator and ammeter stud, preferably as close to the alternator as possible