Replacement Alternator - BBC

[mtm87tx]

Team,

My alternator is not properly charging and I am looking to replace it? Currently it is a what appears to be incorrect 3 wire setup.



My questions for you:

1. Is there a good advantage to converting to a one wire vs a three?
2. How many amps do you recommend? BBC, MSD Billet Ignition, A/C, HID lights, wanting to add stereo with amps and power windows/locks

Thanks for the recommendations.

[astroracer]

Team,

My alternator is not properly charging and I am looking to replace it? Currently it is a what appears to be incorrect 3 wire setup.

My questions for you:

1. Is there a good advantage to converting to a one wire vs a three?
2. How many amps do you recommend? BBC, MSD Billet Ignition, A/C, HID lights, wanting to add stereo with amps and power windows/locks

Thanks for the recommendations.

No advantage going to a 1 wire. The 3 wire set-up uses a sense wire which connects to the main distribution block to "sense" how much current is going thru the block. This tells the alternator how much current to produce. Every time you turn on accessory the current demand goes up. Without this sense wire the alternator only sees higher current demand then what the battery is charged to. GM's 3 wire system works well and there is no valid reason to change from it.
1 wire alternators are used on vehicles like tractors and stationary pumps, where there are no accessories, to simply keep the battery charged.

You need to add up all of your accessories draw numbers to come up with a real number. Different units/manufacturers pull varying amounts of amps.
Mark

If you want to learn more about the 3 wire/ 1 wire debate go here:
http://madelectrical.com/electricalt...hreewire.shtml
Lots to read and learn here so bookmark it and read at your leisure.

[MonzaRacer]

Napa number 1N4605G, its new. 1N4523DHO. Second one is even higher amp unit, AND I recommend adding an 8ga charge wire in place of factory 10ga. OR MAY have to use drill bit to ream mounting hole but not much. some already fit bbc lower bolt. on plug use large wire looped to battery terminal.
use either EC268 4 wire or 787128 from napa. on the one with 2 wire the open port, if I remember correctly, would go for a tach signal.
I also have diagram attached, the critical wire is the 12 turn on from idiot light (if regulator sense no output that line goes to ground and turns on light. Forget older car colors off hand, been sorting Ford wiring lately and memory is all on ford crap wiring. I ran the AC Delco version on my BBC and sbc from 94 through 06 or 07. Still got it waiting to get it rebuilt or traded in.
Pushed car, electric fans, stereo, etc easily. AND can be had at most parts stores.

[mtm87tx]

Ok just a quick update on this, found out the alternator I have is a PowerMaster 140AMP. I had it tested and both the diode and power regulator were bad so I replaced these. After additional inspection I noticed my charge wire was a 16ga so I changed this to a 4ga (wire I had)

Question still, with a test 140AMPs out and the battery at 14.5v idling with no A/C when I turn this item on (fan and compressor clutch) I am dropping below 13v still.

Any thoughts?