Alternator wires! HELP!

[Al1940]

I am helping my friend Al with his '68 Truck. He's 77 and doesn't remember why he cut these wires!
I have found a new passion with fixing his truck because he has all the tools to do it with.
The truck starts and runs well but when I pointed out the wires he doesn't have a clue, but may have had a trailer at one time.
The off-white wire and blue wire behind the alternator was cut. Are they necessary?
The white wire coming from "dual battery indicator", middle bolt, cut as well. Not the same thickness or exact white as cut alternator wire.
All help is appreciated.
Thank you!

[VetteVet]

Originally Posted by Al1940

I am helping my friend Al with his '68 Truck. He's 77 and doesn't remember why he cut these wires!
I have found a new passion with fixing his truck because he has all the tools to do it with.
The truck starts and runs well but when I pointed out the wires he doesn't have a clue, but may have had a trailer at one time.
The off-white wire and blue wire behind the alternator was cut. Are they necessary?
The white wire coming from "dual battery indicator", middle bolt, cut as well. Not the same thickness or exact white as cut alternator wire.
All help is appreciated.
Thank you!

On a stock truck these wires control the output of the alternator. If he has this alternator then those wires have to be connected.



They come from the external voltage regulator on the radiator support.

If he has this alternator then some one has converted the truck to an internally regulated alternator and the blue and white wires are not needed depending on how the conversion was wired.

[bill3rail]

What alternator is on the truck? CS or SI or externally regulated?

Pictures help immensely!

Bill

[Al1940]

It's a SI, model Ultima 01-0039. How do I know if it's externally regulated? New pic is old alternator, now I know where white wire from dual battery indicator came from, but need to know where to attach on new alternator.
Thank you

[Al1940]

It's a SI. New pic is old alternator, now I know where white wire from dual battery indicator came from, but need to know where to attach on new alternator.
Thank you

[VetteVet]

Originally Posted by Al1940

It's a SI. New pic is old alternator, now I know where white wire from dual battery indicator came from, but need to know where to attach on new alternator.
Thank you

Look at the plug on theexternal voltage regulator and see if you can locate a brown wire on the end of the plug. This wire comes from the firewall plug by the master cylinder. It starts at the key switch and ends at the voltage regulator plug. You need to remove this wire and run it to the alternator and connect it to the no, 1 terminal on the alternator.

Then locate the red wire in the regulator plug and run it to the no.2 terminal on the alternator.

Here's a picture.



The wires will plug into the rectangular hole on the side of the alternator, and
you can buy an adapter at autozone or any of the -parts stores and splice the two wires into it.



This should make the alternator charge and if you check the battery with the engine running you should measure 14 volts + or - a half volt.

[Al1940]

Thanks VetteVet-
Tomorrow's project. Will let you know the outcome!