Holley EFI guys what alternator and how to wire it?
 

Good afternoon guys,

Question I am installing Holley HP EFI with a new 4150 flange multi-port intake on my Baja 252 with a Big Block 509, I am curious what you guy's are doing for an alternator and what's the best way to wire it? I rather not use any of the old MEFI 1 harness as it is old and not in the greatest shape.

One wire alternator that goes on the starter terminal.

GM marine 1 wire to the... I don't remember where I terminate it at. I'll look into that. Either at the battery or starter.

I'm using a 140 Amp internal regulator alternator. I had it wired as a 1 wire for a while, but changed it to 3 wire to get more voltage at idle, if I turned the stereo up too loud it would shut off because system voltage went lower than 12.5 volts. With it wired as a 3 wire it knows the system voltage, and can up the charging when needed.
Main cable goes to the starter, F terminal to ignition, jumper from positive post to R terminal.

Straight to the starter (bottom) terminal... same as the fuse.
https://cimg8.ibsrv.net/gimg/www.off...382cdcc30d.jpg

I had that wire custom made somewhere.

Anyone have a part number on the alternator? I want to order it today. I want the 140amp I do not want to worry about amperage output.

I currently have a summit brand SUM-810344, not really "marine rated" but works just fine for me so far (I would imagine it would get more wet under the hood of a car than under my hatch anyway).

I agree but I think its more about being explosion proof then moisture proof? you don't get the fume buildup under a car hood like you can under a boat hatch I would think.

Oh yeah...well the boat still hasn't exploded yet either!

HAHAHAHAHAHA that's a good thing please keep it that way LOLOL

Do yourself , and your passengers, a favor a get the spark arrestors , (or marine alternator itself)for the alternator. Favor is just a figure of speach.

You just haven’t gotten enough fuel vapor's in your bilge yet.

You have smoke detectors and etc in your house ?

Fyi: only one person loses in Russian roulette.

and yes I’ve seen , in person, probably five boats now engulfed in flames.

SB - All the alternators I see marine rated none of them are 100amp or more and I do not want a automotive unit in my boat for the obvious reasons. Can you recommend one so I can get it ordered and check this box?

I've been using these for almost 20 yrs.
https://www.dbelectrical.com/product...ch-140amp.html

I was just on their website too. going to order one up now.

Or take your marine Alt and find a local Alt and Starter repair/rebuild shop. There's one around my area that ive had them take a standard 80amp and build it to a 160 amp in the past...