Alternator Upgrade Situation

[Razzman]

So how do you figure what alt amperage you should have? I don't even know how to figure the total amps of the stereo system! :confused

[spharis]

Your amp manufacturer will list max amp draw, or you can go off your fuse ratings (easiest) then you can figure you draw for you electrics....in boats probably 15A or less. Then add 40%......that's what I do anyway.

I figure most boats are fine with 90A, but its always better to have more than you need. I like the fact that my battery will be charged within 5 minutes of running my engine.

[Domsz06]

Your amp manufacturer will list max amp draw, or you can go off your fuse ratings (easiest) then you can figure you draw for you electrics....in boats probably 15A or less. Then add 40%......that's what I do anyway.

I figure most boats are fine with 90A, but its always better to have more than you need. I like the fact that my battery will be charged within 5 minutes of running my engine.

i agree, more is better in this sense, so then it doesn't have to work nearly as hard when you do push it!

[spharis]

My 150A alt is in....no major issues, save undoing all the factory wiring to clean the wiring up some. I ran 2AWG to the starter lug where it meets 00AWG to the battery. Had to adjust the alternator bracket, and redo wiring harness from the carb out to the sensor after it. All in all about a 3 hours job, half of which was spent crimping hard lug terminals, pulling the hood, trans cover, seats, and mopping up some old water in the bilge.

The following are my readings with bilge pump, lights, nav lights, blower, and stereo on @ idle.
Before: 11.8A
After: 14.2A

I can't even see the needle fluctuate if I run about 200RPM over idle.....I could probably power two more boats with a set of jumper cables

[chpthril]

Sounds good dude!

[spharis]

I am complete;y stoked....I can't wait to get it out on the water next weekend...

[Coach]

Where did you pick up the Alt? How much did it run? Are you using any thing like the balmar products?

http://www.balmar.net/

[spharis]

I am going to add a 200A stinger isolator with the second battery. No switches.

I got it from DB electronics in TN. They are manufacturers for Jegs, Summit, and other performance parts wharehouse brands. Most of the alts they sell are hand wound, and they can build one to your specs as requested. I think business they do outside wharehouses is done on ebay. You will not beat the pricing they have. It was ~$150 shipped. Comparative model from elsewhere runs in the $300 range or more. If you want some in depth detail, PM me. Their low prices are not because of quality, rather they don't like screwing people like other manufacturers do. If you have ever heard or Iraggi alts (big in car audio) or stinger, DB has started to take alot of their business, so much so, Iraggi price matched a recent group buy DB had going. I am also running a DB alt in my tahoe. It was pushing 1800watts at idle with no headlight dimming. I did have to overdrive it with a new pulley, but that was all.

[Domsz06]

sounds like a bad to the bone alt, can't wait to get one!

[Moki]

OK - I am ready to install a new alternator

Spharis (Darth - Anakin)

I am ready to order a new alternator and isolator from your contact. Below are pictures of my alternator:

PS Do you like my stray wire coming out the back.-- that looks real safe.

[Jeff T]

I didn't want to bring this thread back from the dead, but I thought I would give a quick update.

I have placed an order with DB Electric for a 140 amp Delco alternator and a 140 amp battery isolator. Total shipped was $190.

This alternator is normally a one wire, but he is making it a three wire. Also, he will be labeling all wires for me based on my current alternator (he used numbers off my stock 65amp to look up which wires are needed). Attached is a picture of the alternator. The picture is a one wire instead of a three wire.

As for mounting, there will be "slight" modifications. The lower bracket bolts directly into the block. I will have to loosen that bracket, rotate it down 1/2inch, and retighten. Lastly, my stock alternator is actually mounted upside down. There are two mounting tangs on the alternator that marry up to the boat mounting brackets. The new alternator only has one instead of two. I will have to buy a longer bolt that will reach all the way through both mounting brackets. I will also have to add a spacer between the two mounting brackets. I hope that made sense. The pic of the new alt shows the alt right side up. To mount in my boat, the alternator will be flipped where the wiring is on bottom.

If for any reason it doesn't mount up like it should, Ron guaranteed money back. Ron was excellent to work with.

**EDIT**
I couldn't repost the pic of my current alt because I already posted it. It can be referenced in post #19. Sorry about that.

[Domsz06]

that's sweet, i'll have to get one soon.

[Razzman]

Yeah i have to do it to, the alt in mine is only a 55amp.

[spharis]

I think I sent everyone info on how to get in touch with these guys. If anyone else needs, PM.

Jeff....I also had to make minor modifications to mount mine in due to the ears being a little different. The results were worth it.

[Jeff T]

I think I sent everyone info on how to get in touch with these guys. If anyone else needs, PM.

Jeff....I also had to make minor modifications to mount mine in due to the ears being a little different. The results were worth it.

I may get back in touch with you when installation time rolls around. I'm aiming for the first or second week in March. I would like details on the actual installation (more how to get the belt off, etc.). I've neve done it, so i don't know.