This is for a 66 c10. Where does it go, mine goes from the regulator #4 position to the fire wall connector but does not go anywhere on the connctor in the cab, the space in the connector is empty and my charging system is not working. The truck wiring was hacked up by the po so i printed the wiring pics from this site but that wire does not exist in the cab. It was wired by a hot wire from the battery to the f pin on the alt. Then the blue and white wires were tied together and put on the other pin of the alt, it worked but was not right according to the wiring prints. My alt has a lug for the bat + and a lug for ground and 2 pins on the back for some wires. Please help, Thanks
Greg

If at all possible, switch to an internally regulated alternator. A rebuilt one should be about $35.00. Wiring is really simple for an internal: 12v terminal to battery, ground to ground, and a small wire to go to the dash idiot light.

Here's a thread with a wiring diagram. It shows the brown wire from the regulator to the bulkhead connector. One brown wire goes to the ignition switch and another one goes to the generator light.
Shadetree is right about the internal regulator. You will be much happier with it.
http://67-72chevytrucks.com/vboard/showthread.php?t=193429

Thanks, i am looking into it. Greg

I cant read that small print, i pmed the guy to email me one but have not heard back yet. I used the wiring from this site http://pages.zdnet.com/64moneypit/id18.html and as you can see on the 66 v8 wring print the brown wire goes to the bulk head conn. Then go to the 66 dash print there is no wire coming from that location. I cant tell if that colored print you suggested is like this or not. Hopefully he will email me the colored print soon so i can figure out what is wrong. Thanks
Greg

I saved his print to my hard drive and then used the magnifier on my picture manager to view it. it runs like I said in the other post. If it works like the 67 and up years then you can run it through a resister to the key switch and it will charge. I will see if I can find that thread. VV
I found this in a website on changing to internal alternators.
And what about the idiot light? Well, the electricity that goes to energize the alternator (through the brown wire) comes from the idiot light. This leads to an interesting tid-bit, the alternator needs to see some resistance in this line. That resistance is the bulb! If you try to be "custom" and use a LED, there isn't the correct resistance and the alternator will not work correctly! You can't just by-pass the light!

I saved his print to my hard drive and then used the magnifier on my picture manager to view it. it runs like I said in the other post. If it works like the 67 and up years then you can run it through a resister to the key switch and it will charge. I will see if I can find that thread. VV
I found this in a website on changing to internal alternators.
And what about the idiot light? Well, the electricity that goes to energize the alternator (through the brown wire) comes from the idiot light. This leads to an interesting tid-bit, the alternator needs to see some resistance in this line. That resistance is the bulb! If you try to be "custom" and use a LED, there isn't the correct resistance and the alternator will not work correctly! You can't just by-pass the light!
I also saved it into my computer and magnified it, gets too distorted to read. Can you email me a good readable one the size i can read to Greg2637@sbcglobal.net
Thanks
Greg