Charging issue?

[Bunky]

So my 67 had the internal regulator alternator on it but it was wired funny. So I re wired it to a post I found on here. The generator light never came on in the on position, but it did in the acc. Position (I know why this is ). So like I said I rewired the alternator correctly but the generator light doesn't come on when the engine is off but key is on.. I have grounded the blue wire to make sure the circuit is good, and do have 12 Volts to the alternator..

Do I have a bad regulator or ground ?

[kwmech]

I guess from your statement It still may be a wiring issue. Can you sketch up what we're dealing with. Going to an internal is not rocket science. What I've done for these is peal the OE wiring harness back to the regulator and remove the blue and white wires. I loop the bat post to #2 and extend the brown wire to #1 and of course reconnect the red to the batt post. This would be for the 10 and 12 Si alternators

[Bunky]

So that is basically what I did,. Kept the original red wire to the post on the alternator, took the red wire off the connector and ran it to the alternator post as well, and hooked the white wire (brown on my connector) to the blue wire going to the regulator and connected the blue wire at the regulator to the brown wire at the regulator which comes from the firewall. I'm pretty sure the alternator must be bad because I have everything hooked up the way it should and if I ground the connector on the alternator the generator lamp lights. I will take to to have it checked later

[RustyPile]

Originally Posted by Bunky

So my 67 had the internal regulator alternator on it but it was wired funny. So I re wired it to a post I found on here. The generator light never came on in the on position, but it did in the acc. Position (I know why this is ). So like I said I rewired the alternator correctly but the generator light doesn't come on when the engine is off but key is on.. I have grounded the blue wire to make sure the circuit is good, and do have 12 Volts to the alternator..

Do I have a bad regulator or ground ?

I have to agree with kwmech, you still have a wiring issue. The clue to this assumption is the fact that your charge light doesn't come on when the ignition switch is in the ON position, but does come on in the ACC position.. The brown wire coming off the ignition switch and going to the regulator (whether internal or external) is a resistance wire and the charge light is wired in parallel with it.. The resistance wire is needed in case the charge light burns out. It carries the current needed to "turn on" the alternator when the engine is running. The light goes out when the alternator is charging.

The white wire is the voltage sensing wire. Looping it to the "battery" (big post) on the back of the alternator will work, but that's not the optimum place for it. The best place is to connect it to the main power distribution wire somewhere near the firewall connector.. All wire has "built-in" resistance and the longer the wire, the greater the resistance.. Sensing the voltage a distance from the alternator ensures the voltage appearing near the electrical items is at an optimum level.

Correct the problem with the charge light operation and you'll probably also solve the charging issue.

[EDIT] Here's how I wired my 12SI alternator. The white wire I alluded to above is the small red wire attached to terminal "2" on the alternator.
https://67-72chevytrucks.com/vboard/...0&d=1396037984

[Bunky]

So as I figured in the beginning the alternator was bad, it was one the Previous owner had put on the truck. But the wiring was messed up I fixed the wiring like it was supposed to be and the light didn't come on. Went and got a new alternator and the light is on and 14.50 volts all is good.