Alternator excite wire


Veteran Member
Nov 3, 2015
So, for whatever reason, my 73 has a one wire alternator on it. This puzzles me since as far as i can tell, 73 and up had internally regulated alternators. Anyways, the one wire alternator can also be set up as a 3 wire alternator, which i am going to do. I was hoping i could actually find the 2 wire plug hidden somewhere that i hadn't come across yet. no such luck. What i would really like to find, is the brown wire (i think) that plugged into the alternator, to return it to pretty much stock form, and would make my idiot light work again. When i bought the car, the Gen light was always on. No huge surprise there as to why. It doesn't work anymore, i assume the bulb has burnt out. Where should the brown wire go through the firewall? Did it run up along the firewall to the passenger side? I have looked at the cluster harness online, and i am guessing its tucked in nicely behind the brake booster, it looks like it has a bolt in the center of it. Going under the dash to trace it back out isnt going to work real well for me since every time i do that, the funny way you have to twist your body wrecks my back, and i end up on the couch for 2 days.

I did purchase the plug, with the extra plug that has a diode in it in case i cant find the brown wire. i have a junction block on the inner fender right by the alt that has both switched and unswitched power if i am unsuccessful at finding the brown wire.

Thanks in advance.