Alternator Ground

[gr8scott]

I know the alternator is grounded through its mounting points, but would like to add a ground wire. Would 10 ga. wire suffice?

 

[D.R.Y.]

That's what I used and everything is good

 

[gr8scott]

Thanks D.R.Y.

 

[904Bronco]

Generally, I have been told that whatever size wire is feeding the Alt, the ground should be the same size...
Looks like you have a 130 amp G3... 10G might not be enough?

 

[Steve83]

Right - current is the same everywhere within a circuit. If 130A is flowing through the output stud, 130A is flowing through the case (ground).

 

[gr8scott]

Hmmm...that's kind of what I was thinking. Think I'll up it to 6 ga.

EDIT: Actually, since my main charge wire is 4 ga., should I match it?

 

[904Bronco]

Hmmm...that's kind of what I was thinking. Think I'll up it to 6 ga.

EDIT: Actually, since my main charge wire is 4 ga., should I match it?

The Guy that makes my cables locally would say yes...

 

[Steve83]

At least.

Assume the worst - the block ground fails in some way, leaving nothing but your alternator ground wire. Then you use the starter, which can pull over 250A (again, worst-case). An undersized alternator ground wire could catch fire. It's actually more dangerous to add parallel ground wires than to simply maintain the originals.

 

[Broncobowsher]

Where is the battery grounded to now?

 

[gr8scott]

Where is the battery grounded to now?

The threaded boss on the block right behind the alternator.

 

[blubuckaroo]

Where, on the alternator, do you plan to attach this big ground wire?

 

[gr8scott]

I'm thinking between the spacer and the case, so it makes contact with the case.

 

[B RON CO]

Hi, I think there is a ground lug area cast into the back of the alternator, near the bearing. Why not just loop that to the battery ground?

 

[gr8scott]

Hi, I think there is a ground lug area cast into the back of the alternator, near the bearing. Why not just loop that to the battery ground?

That would look a lot cleaner, thanks.

 

[gr8scott]

FYI, that bolt size is 8x1.25. Well, on my 3G anyway

 

[B RON CO]

Hi, happy to help. How is your volcano doing?
Good luck

 

[gr8scott]

The volcano is on Hawaii island, or the Big Island as we call it. And its flowing like a flash flood river all the way to the ocean.
When it comes into contact wit seawater it creates LAZE (lava and have) which in a nutshell is a hydrochloric acid plume that carries
fine particles of volcanic glass. Nasty stuff. I live on Maui, one island over. There's a member here that lives there, can't
remember his name. Hope he's okay.

[youtube]NsFc95JZey4[/youtube]

 

[blubuckaroo]

The threaded boss on the block right behind the alternator.

So, if you're going to use the same point of ground that the engineers did with the mounting bolt, I can't see a ground path improvement.
Just make sure the bolts are tight and you'll have the same ground.
All you're going to do is add a big wire.

 

[gr8scott]

The mounting bolt screws into the head, not the block.

 

[blubuckaroo]

The mounting bolt screws into the head, not the block.

I'd think the ten cylinder head bolts would carry enough current.