BE Alternator Wiring Question

[erstearns]

I have installed an alternator, changing over to neg ground and eleminating the control box. I have a new wiring harness that has what appears to be a 12 gauge yellow gen wire.

Can I run a single 10 or 8 gauge wire from the B+ alternator terminal to the battery side of the mechanical starter switch (or to the positive terminal of the battery) and eleminate the 12 gauge yellow wire that would get bundled with the other A & A1 control box wires?

 

[spritenut]

You have to connect the brown, the brown/blue, and the yellow wire together at some point.
So if you connect it to the hot side of the solenoid, you still have to connect the brown & brown/blue together at the old voltage regulator. They are already hooked together in the regulator but if you eliminated the regulator, make sure all the heavy brown wires are connected.

 

[erstearns]

There is literature and discussion about doubling the yellow wire from the alternator because it is too small as originally wired for a generator. It seems more effecient to run one heavier gauge wire.

If I read the diagram correctly, for converting to neg ground, installing alternator and removing control box, the brown wire picks up current at the battery and distributes it to the brown/blue to ignition and to the always on terminal at the fuse block.

The heavier 10 gauge wire I propose adding is for the charging system and the most direct route is from the alternator to the battery (or to the hot side of the starter switch.

Am I thinking correctly?

 

[Sarastro]

You're right about running one heavier wire. When you double the wire, you don't exactly double the current carrying capability, since the resistances are never exactly equal. You end up with one of the wires carrying most of the current anyway.

The rest of what you are planning sounds right to me.

You need to wire up the ignition idiot light, too. It normally goes to the "D" terminal of the box (yellow wire), which is just the generator output. Alternators usually have a separate terminal for this light, but if not, it can go to the alternator output terminal.

I know you'll enjoy the alternator, or at least the peace of mind it gives you. I made the mistake of installing an ammeter, so I could see how badly the generator kept the battery charged. That really encouraged me to install the alternator in a hurry!

 

[erstearns]

I've got a terminal on the alt for the light wire. Going to run a 10 gauge either to the battery or starter switch and eleminate the 12 or 14 gauge yellow wire on the new harness.

 

[Sarastro]

Sounds like you've got it in the bag!