Another annoying Alternator question

[seik5]

New engine has a 12SI 100 amp 1 wire internally regulated alt. upgrade. New stock engine harness alt. hot wire appears to be too small considering I will have dual fans added. Also have Volt gauge in new elec. gauge cluster. I am thinking all I need to do is add a 6 gauge fused wire battery to alt. Since I have no warning light or amp meter I would not use any other wires. I have not done this before and have zero confidence in my thought process. I just can't find a schematic that covers my situation. Help?

[franken]

Any idea what vehicle this is in? You can't just swap an older alternator for a new style single wire type.

[seik5]

This is on a 72 Blazer with chevy 350. Pretty much a stock crate engine

[seik5]

[attach][/attach]

Where I am at! I am just trying to prewire what I can While tub is getting painted

[SeanB242]

I believe all you need is a heavy ga wire from alt. to a junction box from the battery. That’s how the AAW kit is wired we did.
https://smhttp-ssl-87263.nexcesscdn....t_Design_1.pdf

[Dead Parrot]

Since it looks like a bottom up build, I would think about adding a larger junction block. Better for adding newer accessories. One like this can be found in salvage yards on 90's era GM trucks. Similar can be purchased new. One advantage of the yard block is you can often include several wires with the proper sized ends and with factory assembled fusible links included. A lot of the alternators on this era trucks were in the 78~100+ amp range so the wire is already sized properly. In my pic, it is the easy to spot red wire with the alternator boot near the end. IIRC, this all was priced as a "Misc Electric Part" for either $5 or $10.

[seik5]

Ok thanks for the help guys, I ran a #6 wire through a fuse block and to a larger dist. post that I added. The Distribution Post IS WIRED DIRECTLY TO THE BATTER . I also added an extra # 6 Ground to the alternator. This all came in a Kit and worked really well. Now wondering about that original little #10 power wire. I know it goes back through a junction in the harness through a fusable link to that small little [stock] Connection block. and then to the battery. That connection in th harness also sends power to the cab connection. So Its makes sense to leave that all hooked up. But I need help at the alt. Do I need to hook it up there as well. I could also hook up the original ground, its all there if I need it. Otherwise I might just tuck that original harness out of sight or better yet get rid of it, since I am running a volt meter with no warning light. in my new gauge cluster I don't plan to hook up the other wires at all.

[VetteVet]

I am not aware of any #10 gauge wire in the original harness. The no.12 gauge wire that I think you are referring to is pictured in this diagram. It runs from the alternator to the small soldered junction in the OEM harness and to the battery. It also feeds the cab through the firewall junction.








Here is a smaller version with the junction circled.





The 18 b/w and the other 18 ga. black wire at the battery junction are for the battery gauge in the gauge dashes. The charging light dashes do not have these two wires in the harness.

[seik5]

Thanks that diagram is exactly how my original system was wired. With the upgraded internally regulated 1 wire 100 amp. alternator and gauges I added a 6 gauge power wire back to the battery, So my question is What to do with the original red power wire at the alternator would it hurt to just leave it hooked up? I have removed the plug for the volt reg. And since I have a volt meter in my dash Would I just not use the blue and black in the little plug? I also upgraded the ground but see no reason to not use the old one along with the new one>

[VetteVet]

Originally Posted by seik5

Thanks that diagram is exactly how my original system was wired. With the upgraded internally regulated 1 wire 100 amp. alternator and gauges I added a 6 gauge power wire back to the battery, So my question is What to do with the original red power wire at the alternator would it hurt to just leave it hooked up? I have removed the plug for the volt reg. And since I have a volt meter in my dash Would I just not use the blue and black in the little plug? I also upgraded the ground but see no reason to not use the old one along with the new one>

The wires in the plug for the regulator are not needed if you have a one- wire alt. They should be brown red white and blue. I would keep the brown and red in case you ever want to use a three wire alternator. the brown is the exciter wire for the alternator and the red is the voltage sensor for it.

Ok thanks for the help guys, I ran a #6 wire through a fuse block and to a larger dist. post that I added. The Distribution Post IS WIRED DIRECTLY TO THE BATTER . I also added an extra # 6 Ground to the alternator. This all came in a Kit and worked really well.

Lets clarify this.
Your alternator is a one-wire with only the power output wire 6 ga. correct.
This wire is run to a distribution block: correct
Your battery also connects to the dist. block: correct
The original 12 ga. red wire on the alternator is not connected but runs to the original soldered junction in the circled diagram: correct?
The wires in the original diagram are still connected in the harness to the battery and the cab fuse box. Yes no.


This diagram is one I usually post when the question of a junction block(distributor block), is posted. I think you have something similar. You will notice that there is a smaller red wire from the alternator directly to the battery. Then a larger 4 ga wire to the main junction. The loads are all fed off the junction and the battery can still power the truck circuits in case the alternator fails. It would discharge quickly in that case, though.
If you still have the original soldered junction in the harness connected to the cab and the battery then you can just leave the original red wire connected on the alternator output terminal.

[seik5]

Yes to all clarification questions.

I have new 6 gauge hooked to dist block via a 200 amp fuse. Dist block wired directly to Battery. {Not starter, but I could change that}

Original red wire still hooked up To alternator via Solder connection and original block, and block to battery

Old voltage regulator removed and rewired for 3 wire but I will not plug it in.

Additional ground added Alternator to frame, but I will leave the original hooked up as well

New voltage regulator wired to a switched hot wire and ground.

Does this sound like it will work.. Thanks so so much!

[seik5]

Sorry not voltage regulator, I meant Voltage meter in dash gauge cluster.

[VetteVet]

New voltage regulator wired to a switched hot wire and ground.

This is the one you are referring to?

You can click the edit tab and change the post then hit save to correct your post.

Based on your answers, I think you have it down. Make sure you have all the loads fused off the distribution block and the small wire off the alternator is fusible link protected in case the alternator shorts to ground. It looks really good to me. VV

[seik5]

Done! Thanks for the help. It be a while before I can fire it up, but I will try to remember to post how things go!

[montsb]

Great information here! I am in process of switching my Power Master alternator to internal regulating as well. And upgrading exciter wire. A basic “the big three”. These guys l, I will copy the link for, have very good info and great looking power blocks. Just for anyone that would be interested in this...

http://www.madelectrical.com/index.shtml