High volts
I'll attempt to answer all these...
Don't understand. The firewall has TWO sides, the engine side and the interior. Which side? If you are talking about the ENGINE side, then the bulkhead connector itself is probably to blame
As my upbringing is a little different, to me firewall is the engine side...if I said inside the connector or cabin side of bulkhead connector...well, there ya go.
loss from ign wire bulkhead connector to ballast resistor = > 0.5V (this concerned me-nearly half a volt just in a couple feet worth of wiring!).
I assume? guessing? you are measuring from the engine side of the firewall to the ballast? Assuming your meter is making good connections, it is the CRIMP connections themselves, and that right there is half your problem, no pun, 1/2 a volt!!!!!!
We all know what happens when you assume...but, I took my measurements from the engine side of the bulkhead connector. The difference at batt (+) to bulkhead connector ign terminal, was 0.4V, but measuring from batt (+) to connector at ballast resistor or at VR ign wire was, again >1V. There are no other connectors between the bulkhead connector and the VR/ballast/alt excite wire other than an in-harness splice. And after inspecting the harness, it's apparent why there's a voltage loss-the wires are discolored, corroded in places, and stands are cut in others-that's what I meant...I apologize that you didn't follow that desciption.
I also measured loss from the inside of the cabin from the connector to the ignition switch harness
I do not understand from your description what you are measuring here. I'm guessing? the interior side of the bulkhead connector to the connector at the ignition switch?
Yes
Which wire? ignition run? which SIDE of the ignition switch connector? under-dash harness side? ignition switch side?
I tested all segments, before and after switch to see if the connector was an issue; i.e., terminal connectors for corrosion.
If the last is true, that seems OK.
But this contradicts what you've said all along, if my ignition switch is losing > 0.3V, then it already exceeds your original speculation that there should be no more 0.2V from battery (+) to ignition wire at the VR.
One way to do this is "rig" a long clip lead to the battery hot terminal, and LEAVE it there. "Big stud" on the starter relay is OK.
Now work along the "chain" and be specific, some of these parts of the "chain" are easier to get to than others
The following might be example readings, key on, engine off
Starter relay stud---zero volts
Fuse link at engine side bulkhead connector (unless modified): zero
Fuse link wire at interior side of bulkhead (unless modified): .05 ?? volts
loss here was in the mV...less than 50mV, or 0.05V
ammeter terminals (unless modified): .07 V
Irrelevant as the ammeter is deleted, but loss at those wires is negligible
Ignition switch connector, battery feed, switch side: .085v
Ignition run wire out of ignition switch, switch connector, dash harness side: .098v
Ignition run wire on engine side of bulkhead connector, .1v
Ballast resistor at ignition run wire, .15v
Notice each connector adds a small amount to the mix.
If I understood your last posting, you lost nearly a half volt from the engine side of the bulkhead, in the ignition run wire, to the ballast resistor. The "only thing there" is a crimp connector on each end of the wire!!!!.
Don't forget the wire in between!!!!
The point of me posting those numbers, without running a jumper from here to there and there to there and there to there, was to measure the cumulative loss with the currently installed pieces parts, and detect where the major losses are. My major losses are already mentioned in the previous post, but for clarity sake:
The ignition harness, engine side-replacement imminent...too many cooked wire segments
Likely the ignition switch as the voltage drop of the one currently installed is higher than a slaved in one that isn't even grounded to the column.
Dirty/loose bulkhead connectors...this ought to be fun