Voltage regulator/alternator question (lots of questions)

[shifty]

Started working on the LS1 swap again this weekend. I was getting the wiring cleaned up and further pruning out the engine bay. Ran into some questions, and the Haynes manual ain't helpin so much.

So, I'm using the stock 1-wire alternator from a 2001 Trans Am WS6. I do not know much about alternators - is a 1-wire alternator internally regulated on the voltage? If "yes", this answers a lot of other questions.

I have two lines going into the truck: A fat ass red wire (10g?) and a skinny brown wire. The brown wire goes to the voltage gauge and fuseblock (hot-in-run-or-start). Does anyone know what that fat ass red wire is for? It is in the bottom corner of the fuse block closest to the inner fender, if that helps. I speculate this could be for the lights ... or it could be supplying power to the fuseblock - which is it? What is its purpose?

At this point, I guess I just need to know if both the red and brown wires going to the bulkhead need to have voltage regulated or if they can be straight hot from the battery (with fusible link, I suppose?). Once I get thta figured out, it eliminates most of my wiring woes.

This is just for my reference:

I removed the voltage regulator with four wires coming out of it - red, white, dark blue and brown.
Red goes to the alternator and battery (via bulkhead on pass. side).
Blue and white had a molded connector to tap onto the alternator.
Brown goes to the bulkhead at the firewall, to voltage gauge and fuseblock (hot-in-run-or-start).

If I don't write it down, my memory would surely forget.

[john]

Shifty, this might help some. It shows the 12ga red wire in the eng compartment. It is internally regulated. The brown wire was a switch powered wire to the regulater.

[roughedup72]

The alternater is internally regulated, I think the big red wire is the power wire for accessories, not sure about the brown. I will check the manual and see what I can come up with and post again tomorrow. I'm about to be going to work, 12 hour e shift. Yuk.

[shifty]

Weird - what I'm seeing in that picture is two diff't red wires....

One goes from the junction block on pass. side to the bulkhead (fuseblock).
One goes from the junction block on pass. side to meet up with the alternator and voltage regulator line, then to the bulkhead.

It also shows the brown wire coming off the voltage regulator and to the bulkhead - this wire would be regulated, I suppose?

I am curious what the purpose of the red wire from the junction block to the bulkhead is - This wire did not exist in my setup. I only had the second red wire that was tapped into the alt and volt regulator.

I also wonder what all purposes the brown wire has. My manual shows it is for the voltage gauge inside the cluster, but it has an additional line showing it as "hot in run/start" power also. So confusing ...

[john]

Shifty the brown wire was just a 12v ign wire to regulater. It is not needed with i wire alt. The black and black/white wires with the 4 amp fuses are for the ammeter. They are in the cluster connector if your truck has the guage option.

http://www.geocities.com/chevroletc1070/wiringdias.html

[LockDoc]

Here is the color wiring diagram post from the FAQ. If you are on dialup it will take quite a while to load.

http://67-72chevytrucks.com/vboard/s...ghlight=wiring

LockDoc

[shifty]

I'm on broadband - THANKS guys!

[neonlarry]

Do you have an aftermarket alt? Stock alt would not be 1 wire. If its stock its most likely a CS130 or upgraded CS144. These would take 3 wires.
The red wire from the bus is for fuse block power, the brown wire is switched alt excite power.

[VetteVet]

Shifty here is a thread that may be of some help. How do you know it is a one wire alt?
http://67-72chevytrucks.com/vboard/s...ght=alternator

[shifty]

FYI, just bumping this to the top - I wanted to make sure anyone reading this thread in the future knows:

Delete the regulator. Attach the red wire listed above to battery power. Delete the brown wire (or hook it to ACC power and NOT constant BATT power).

If you attach constant battery power to the brown wire, everything in your truck will have 6-12 volts of power