Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-09-2017, 11:09   #1
Registered User
 
mrybas's Avatar

Join Date: May 2010
Location: East Coast USA or out cruising
Boat: Lock Crowther 150
Posts: 361
Alternator good, not charging battery

I took the battery to an alternator shop that bench tested the alternator and said it was good.
When I reinstalled the alternator, the battery voltage is 12.40 and does not rise when the engine is running (at idle or higher rpm). Any ideas?
__________________

__________________
mrybas is offline   Reply With Quote
Old 11-09-2017, 11:21   #2
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,010
Re: Alternator good, not charging battery

ore info. Internal regulator or external? It sounds like a regulator issue, but if internal and they checked... then that doesnt make sense.
Is the ground cable to the engine block clean? This can be a source of loss of contact... although your engine starts evidently. Is the start battery grounded at the same spot? Battery switch in the right position for charging? Defective battery switch?
__________________

__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 11-09-2017, 11:28   #3
Registered User
 
mrybas's Avatar

Join Date: May 2010
Location: East Coast USA or out cruising
Boat: Lock Crowther 150
Posts: 361
Re: Alternator good, not charging battery

Quote:
Originally Posted by Cheechako View Post
ore info. Internal regulator or external? It sounds like a regulator issue, but if internal and they checked... then that doesnt make sense.
Is the ground cable to the engine block clean? This can be a source of loss of contact... although your engine starts evidently. Is the start battery grounded at the same spot? Battery switch in the right position for charging? Defective battery switch?


The alternator is internationally regulated. The engine is only hooked to the start battery, not a house bank. Alternator and start battery are both ground to engine block, connections are clean.
__________________
mrybas is offline   Reply With Quote
Old 11-09-2017, 11:30   #4
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,820
Re: Alternator good, not charging battery

Check and clean all electrical connections between the alternator and the battery bank including all negative connections.
__________________
The Blue Dot Campaign. This Changes Everything.
DeepFrz is offline   Reply With Quote
Old 11-09-2017, 11:33   #5
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,010
Re: Alternator good, not charging battery

... and clean the battery posts. Sometimes they can be "wet" inside and not show any obvious corrosion. I had this occur on a car. Charge light came on. Nothing wrong. The posts had grey/wet on them inside the cable clamp..
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 11-09-2017, 11:33   #6
Registered User
 
admiralslater's Avatar

Join Date: Sep 2014
Location: Toronto summer rest somewhere else
Boat: Outremer 45/pdq36
Posts: 602
Re: Alternator good, not charging battery

One of my engines ate 2 batteries in 2 years . I checked the out put ,good checked the battery connections ,clean checked every thing I could think of . Will fitting new battery this year one of the really professional looking connections on the battery line fell off . It looked perfect . Yank on every joint and take nothing for granted
__________________
admiralslater is offline   Reply With Quote
Old 11-09-2017, 12:11   #7
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 1,581
Re: Alternator good, not charging battery

All connections are suspect. I usually run a ground and don't depend on the mount for ground. I had an issue where an known good alternator wouldn't charge that was eventually traced to automotive battery cables. When cut open, corrosion ran throughout the cables. Somehow the heavy current of starting would blast thru, but the smaller charging amps would not.
__________________
Lepke is offline   Reply With Quote
Old 11-09-2017, 12:19   #8
Registered User
 
Fence Man's Avatar

Join Date: Dec 2016
Boat: Stardust Cruisers HB 73'
Posts: 160
Re: Alternator good, not charging battery

Test voltage at the alternator. If you're getting 14 at the alternator, you know it's between there and the battery. Sometimes, a self exciting alternator needs a kick start. One wire, or two going to the alternator?
__________________
Fence Man is offline   Reply With Quote
Old 11-09-2017, 12:50   #9
Registered User
 
mrybas's Avatar

Join Date: May 2010
Location: East Coast USA or out cruising
Boat: Lock Crowther 150
Posts: 361
Re: Alternator good, not charging battery

Quote:
Originally Posted by Fence Man View Post
Test voltage at the alternator. If you're getting 14 at the alternator, you know it's between there and the battery. Sometimes, a self exciting alternator needs a kick start. One wire, or two going to the alternator?


I've taken cleaned every connection between the battery, engine ground and alternator. Still nothing.

I took a picture of the alternator before disconnecting and hooked up the same way......could it be wired wrong?Click image for larger version

Name:	IMG_0397.JPG
Views:	208
Size:	82.1 KB
ID:	155895

Red to B+
Black to B-
Purple to D+
Green to W
__________________
mrybas is offline   Reply With Quote
Old 11-09-2017, 13:18   #10
Registered User
 
Fence Man's Avatar

Join Date: Dec 2016
Boat: Stardust Cruisers HB 73'
Posts: 160
Re: Alternator good, not charging battery

Non self exciting, so that takes care of that. Like was mentioned earlier, you could have a corroded cable under the insulation. Do you have a multi meter? If so, you should be able to test right there at the positive and negative posts on the alternator. Unhook it from the battery so you get a "clean" test. You should get 14 volts, give or take a couple of tenths. 20volt DC would be the best setting on your meter(if you have one) to test.
__________________
Fence Man is offline   Reply With Quote
Old 11-09-2017, 13:21   #11
Registered User
 
lateral's Avatar

Join Date: Apr 2011
Location: NZ
Boat: S34 Bob Stewart - 1959 Patiki class. Re--built by me & good mate.
Posts: 674
Re: Alternator good, not charging battery

Quote:
Originally Posted by Fence Man View Post
Non self exciting, so that takes care of that. Like was mentioned earlier, you could have a corroded cable under the insulation. Do you have a multi meter? If so, you should be able to test right there at the positive and negative posts on the alternator. Unhook it from the battery so you get a "clean" test. You should get 14 volts, give or take a couple of tenths. 20volt DC would be the best setting on your meter(if you have one) to test.
Do NOT do this unless you want to replace your diodes.
__________________
lateral is offline   Reply With Quote
Old 11-09-2017, 13:46   #12
Registered User

Join Date: Jun 2013
Location: canada
Posts: 1,603
Re: Alternator good, not charging battery

Check voltage at alternator pos and neg with engine off. Do you get 12.4 there? If not. You have a bad cable or blown fuse.

do again with engine running See what you get there. If you have 12.4 there. Alt is not charging. If you have 14.4 there and 12.4 at battery. You have bad cables.

One of those small wires is probably ignition. And should also have 12v while running. Otherwise it will not charge.
__________________
smac999 is offline   Reply With Quote
Old 11-09-2017, 13:57   #13
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,637
Re: Alternator good, not charging battery

Quote:
Originally Posted by lateral View Post
Do NOT do this unless you want to replace your diodes.
__________________
Seen on Facebook:

"The Flat Earth Society Has Members Around the globe"

senormechanico is offline   Reply With Quote
Old 11-09-2017, 14:17   #14
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,010
Re: Alternator good, not charging battery

Quote:
Originally Posted by Fence Man View Post
Test voltage at the alternator. If you're getting 14 at the alternator, you know it's between there and the battery. Sometimes, a self exciting alternator needs a kick start. One wire, or two going to the alternator?
I'm not sure this will work if the alternator is not being "excited" ..... ie: no low voltage to sense so it doesnt kick on and put out 14+ volts...?

I would also be careful about auto parts store testing... IIRC I had a starter that tested fine, but under load it didnt work. Been awhile...
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 11-09-2017, 14:47   #15
Registered User
 
mrybas's Avatar

Join Date: May 2010
Location: East Coast USA or out cruising
Boat: Lock Crowther 150
Posts: 361
Re: Alternator good, not charging battery

Quote:
Originally Posted by smac999 View Post
Check voltage at alternator pos and neg with engine off. Do you get 12.4 there? If not. You have a bad cable or blown fuse.

do again with engine running See what you get there. If you have 12.4 there. Alt is not charging. If you have 14.4 there and 12.4 at battery. You have bad cables.

One of those small wires is probably ignition. And should also have 12v while running. Otherwise it will not charge.


Engine running or off, 12.4V at alternator and battery.
__________________

__________________
mrybas is offline   Reply With Quote
Reply

Tags
alternator, battery, charging

Thread Tools
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
Good Food, Good Flavor, Good Value, Good Packaging Steady Hand Provisioning: Food & Drink 22 23-05-2016 16:26
Alternator Battery Charging KJINTF Electrical: Batteries, Generators & Solar 13 27-12-2010 11:52
Alternator Tested Fine but not Charging svstrider Electrical: Batteries, Generators & Solar 1 03-03-2010 03:13
Alternator Is Not Charging gonesail Electrical: Batteries, Generators & Solar 4 28-12-2009 20:40
Alternator Not Charging Batteries pacmaann2 Electrical: Batteries, Generators & Solar 14 01-09-2009 09:18


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.