I ordered some stuff to swap to a GM alternator since mine doesn't put out much even with new alternator, regulator and battery.. Volt meter reads 12.8 when idle and 12.3 if I have radio and heater fan on.. It makes for some iffy starts!

I bought a bracket kit from low range offroad for $42 and a 100 amp GM 3 wire alt from SummitRacing for $105..

This better be worth it.

Anyone know what wire to hook into for the charge light?

 

There are plenty of write ups online. I have some info. Ill see what I can dig up. Is it the 12SI or the later type case? I have a few ideas in mind to do the same. The smog pump bracket on the pass side works great for a "2 ear" type alt case. It also keeps it away from the heat of the header. I cook stock 50 amp'rs about every six months. Combination of high load, high local temps and high rpm toasts them. I was thinking about putting a different pulley on a GM type to actually slow it down. Brings idle output down but since its so much higher its a push for many setups. But at high engine rpm it doesn't spin as fast inside.

I also learned the older GM SI cased units and newer ones (forgot case code) have interchanable pulleys. So you can get any junk yard single or double groove v belt pulley, or an off the shelf chrome dress up type. On chrome I suggest taking a file/sander to the wear surface since the chrome is slick. And if you ever plan to swap to serp belts for some reason you can swap that back easy enough. I'd keep it V belts, since there's only one circuit needed if you keep the alt with the water pump.

As for the reason I mentioned a double groove pulley; the crank has 2 matching groves, but the water pump doesn't. Get a second pulley, cut the center off to slip it onto another. Weld it up. Then you can run 2 parallel belts for the crank/water/alt circuit. The extra load can sometimes squeal a single belt in our cold NW weather coming up.

Hope this helps.

 

And I highly suggest running a large (4-00 gauge) wire from the alt to the + battery post, but also hook the stock line up from the alt to power the stock harness with potent power. Small leads reduce flow and heat things up.

 

It's a 10si case with a single v belt pully.. And what you just said really makes sense about the high rpm killing them.. I drive 20 miles a day doing 3500rpm steadily, sometimes 4000rpm if I feel like pushin it. I might have to change to a larger pully..

I'm definitely going to run a big wire to the battery. But Why do I need to hook up the stock harness when it gets power from the battery?

 

My theory, why not. Sounds silly, but really, it won't hurt anything. And if its going in the stock location the wire is already there. Instead of taking it out hook it back up. Take lots of pics. Guys were just talking about it for the late models the other day here. Maybe we can all combine info into one large upgrade how to.

 

I'm gonna clean up all my wiring when I do it, since I rushed with my HIDs and it looks ghetto

I'll try to remember to take a lot of pics!

I still have to figure out what wire to hook into for the charge light..

 

The 12si I got from High Output Alternators & High Torque Starters is a polished billet cased unit ,150 amp out /100 @ idle, with a smaller 2'' pulley, as I have a under drive crank pulley & want good output though all rpm ranges. They also supplied a connector that ties the stock plug to the GM unit!
I've been running this for a few years now no problems @ all!!

 

Here's the one I bought: http://www.summitracing.com/parts/tff-7127ni
It will be easy to wire up, looked it up and many people say to loop one terminal in to the main terminal to the battery then the other goes to the charge light.. Hopefully I won't fry this thing doing highway speeds everyday!

I don't really care if I have polished stuff, as Im OCD and would have to keep it clean! im not a big fan of chrome/polished stuff especially when theres a lot of it.. Just not something i loke. And the black powder coat will go good with the motor I'm building since everything will be bright green, black or silver/clean aluminum, with a polished valve cover on top.

 

Well, I got my mounts kit and alternator today! Nothing like feeling like christmas a month early..

I also went and bought the connector for the alt so it will be clean looking and 6 gauge wire for going to the battery. My wiring is hopefully going to look perfect when Im done!