72 duster firewall wiring questions ???

tnts72 said

Sigh of relief! I have 12 volts on the brown wire!!! I completed the Mad Mod and ran a 14 gauge blue wire through the bulkhead while I was at it. Had to untape the looms while wire tracing and soldering / splicing under the hood and a little in the car. I also added a signal wire off the keyed 12 volts to actuate my new relay for the autometer dash. Once I get things a bit more tidied up I will put up a conversion thread. Thank you guys for the advice and the wisdom! So much more to learn about these Mopars, one thing at a time. Feel like I owe you guys a beer at least!

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Now that you've made all this progress you STILL (sorry!!) need to check if you are "in the zone."

That is, STILL might be voltage drop in the ignition switch or it's connector

Clip your meter to the blue "ignition run" wire. Do so with everything hooked up "normal" as you want current drawing on the igntion / VR / field circuits

Hook the remaining meter probe to the battery POS. This will measure voltage drop directly. With the key in "run" but engine stopped you are hoping for a very low reading, the lower the better. More than about .3V (3/10 of a volt) you need to pay attention to ign switch and connector

Another "way around this problem" is to have the blue "run" wire key a relay, and feed your underhood loads off that.

Voltage drop in this circuit causes OVER charging, because the VR has to make up for it, and jacks up the voltage at the battery.