Cruisers Forum

Join CruisersForum Today

  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
Thread Tools Search this Thread Rate Thread Display Modes
Old 06-07-2009, 09:29   #1
Registered User

Join Date: Dec 2007
Location: Port of Brownsville, WA
Boat: Ericson 39B
Posts: 34
How to Wire an Alternator

Hey All,

I have your basic alternator at this time, it is a 65 Amp Delco Alternator. On the back it has 2 wire terminals, One says battery and the other is blank. Where should I run the one that says battery? To my engine batteries, house batteries or to the back of my battery selector switch (which just says 1 or Combination on it). And then where does the second wire go too? These two terminals are the ones with the big bolt to hold the wires in place. I have two other wire connectors also, they are the small male terminal type. I assume that these two wires will go to the Amp meter. I would like to use the Amp meter on my electrical panel and not the one outside at my engine control panel.Could someone please tell me the best way to wire up an alternator so both my house and starter battery get charged properly. Thank you so very much.

Sea Maid is offline   Reply With Quote
Old 06-07-2009, 09:38   #2
Registered User

Join Date: Feb 2008
Location: Cruising
Boat: Jeanneau 38 Gin Fizz- Rhosyn Mor
Posts: 331
Sea Maid,
it all depends on how your batteries are wired up. In general the large terminal that says BAT should be a battery cable running directly to your motor bank. THe two small male terminals should be marked. where they go depends on if tis an external or internally regulated alternator. Assuming its externally regulated those two small terminals ( which are marked " f" and "r" go to the regulator and the starter switch "f" is the excitation wire that goes to the starter switch and "r" goes to the regualtor. Get a copy of Calders Book electrical and mechanical maintenance for boat owners, it will help a lot.
If the alternator is internally regulated the two male terminals go to the starter switch and amp meter ( I think I have this right)
hope this helps

Rhosyn Mor is offline   Reply With Quote
Old 06-07-2009, 10:34   #3
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,700
There are as many different alternator configurations as there are brands of coffee. If you start moving wires around without knowing where they need to go it could get expensive fast. You either need help, or first read a book like Calder and seond figure out WHICH 65 amp Delco alternator you have and how it is regulated.

PS-- The best part of Rhosyn Mor's advice is to read the book--I don't think the guesses as to which terminal goes where are correct.
donradcliffe is offline   Reply With Quote
Old 06-07-2009, 10:51   #4
Senior Cruiser
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 36,581
Images: 241
Check out the Delco-Remy Instruction Sheets & Service Manuals:
Goto ➥ Delco Remy
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

GordMay is offline   Reply With Quote
Old 06-07-2009, 11:40   #5
Registered User

Join Date: Dec 2007
Location: Port of Brownsville, WA
Boat: Ericson 39B
Posts: 34
Thank you, Thank you, Thank you. I have the basic 12v electrical book, now I know which book I really need to have and Gord thanks for the link to the Instruction and Service Manual. I love this site. Thank you again for taking the time to write back.
Sea Maid is offline   Reply With Quote
Old 06-07-2009, 14:17   #6
Registered User
mesquaukee's Avatar

Join Date: Jun 2009
Location: Western Caribbean & ocassionaly inCanada
Boat: Mesqua Ukee, Buccaneer 40 (Salar 40)
Posts: 480
On that size of Delco Remy alternator (100 amp and less) the two male spade connectors that peak up through a square shaped hole have nothing to do with an ampmeter. One of them is labelled #1 and should be on the left when looking at it from the rear. You need a jumper wire connecting this terminal #1 to the battery terminal (+ive, usually mounted on a red plastic insulator) on the back of the alternator.
The one labelled #2 is used in combination with #1 for an optional external regulator.

If you want to hook up a tachometer you will have to open up the case and attach a wire to one of the terminal screws on the diodes and lead it out of the case. It is easy to do. When you open the case make sure that the field coil inside stays with the rear side of the case and not the side with the pulley. You may damage some leads to the field coil if you pry it the wrong way.
You will need to temporarily secure the brushes with a short length of wire when you reassemble. The brush holder has a set of holes that line up with a hole in the aluminium case. Insert the securing wire through here. Simple.
mesquaukee is offline   Reply With Quote
Old 06-07-2009, 14:20   #7

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 15,129
Seamiad, Delco and Delco-Remy (two different companies) both have toll-free numbers and will gladly help you to identify your alternator, and then wire it up correctly. They have most of the technical materials available online as well--but they're really, really, helpful folks.

If that is a standard alternator, it is only meant to charge one battery/bank. Making it work properly for two involves some choices and compromises, you can see those detailed on Blue Seas' and other marine electric equipment web sites. Battery swtiches, power combiners...a number of options to suit your budget.
hellosailor is offline   Reply With Quote
Old 07-07-2009, 14:49   #8
Registered User
cdennyb's Avatar

Join Date: Jun 2007
Location: Northern California
Boat: finally a catamaran dive boat...
Posts: 505
Send a message via MSN to cdennyb Send a message via Skype™ to cdennyb
You're incredible ability to be a human Google machine never ceases to amaze me... LoL

What a guy.


the perfect dive boat is one you're on...
cdennyb is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rerigging, old wire or new. skipmac Deck hardware: Rigging, Sails & Hoisting 12 27-03-2009 11:00
Tinned Wire: Charlie Electrical: Batteries, Generators & Solar 56 08-06-2008 19:39
wire chart ? cooper Electrical: Batteries, Generators & Solar 30 22-03-2008 15:36
best place to get wire? jumpnkd Construction, Maintenance & Refit 6 21-01-2007 03:22
Wire irwinsailor Construction, Maintenance & Refit 35 30-03-2006 06:10

Advertise Here

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 08:45.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.