Reply
 
Thread Tools Display Modes
 
Old 03-09-2010, 06:33 AM   #1
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
Alternator Failing?

2000 model Cummins 5.9 ltr 330 hp.

Sunday, while idling around waiting to join the fleet review parade at YC, I noticed that the voltage meter was down around 12 volts instead of the normal 13.8. Occasionally it would jump back up to 13.8 then drop again and when I increased the throttle it went to 13.8. When cruising at higher rpms it remains steady at 13.8.

Is it starting to fail?
__________________
Advertisement

Doc is offline   Reply With Quote
Old 03-09-2010, 08:26 AM   #2
Guru
 
Capn Chuck's Avatar
 
Join Date: Jan 2009
Posts: 899
Alternator Failing?

Doc, Maybe and maybe not. You may start with checking all of the wiring connections followed by a check of the alternator using a quality digital voltage meter AT THE ALTERNATOR and then again at the gage. If you get a good reading at the gage but it still shows erratic readings, you may need a new gage. Look at the least expensive fixes first. Don't forget to check the belt tension. Chuck

-- Edited by Capn Chuck on Tuesday 9th of March 2010 09:27:13 AM
__________________

Capn Chuck is offline   Reply With Quote
Old 03-09-2010, 08:37 AM   #3
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
Alternator Failing?

I forgot to mention that this engine also has a post heater in addition to a pre heater. When you first start it the voltage is drawn down to 12 until the engine warms up for a minute or so unless you increase rpms above 1000 or the heater kicks out.

Maybe the post heater kicked in idling around in the cool water?

Back to the alternator...do these things have stages where the low rpm diaodes? may be failing?

-- Edited by Doc on Tuesday 9th of March 2010 09:38:25 AM

-- Edited by Doc on Tuesday 9th of March 2010 09:39:01 AM

-- Edited by Doc on Tuesday 9th of March 2010 09:40:12 AM
Doc is offline   Reply With Quote
Old 03-09-2010, 11:51 AM   #4
TF Site Team
 
dwhatty's Avatar
 
City: Home Port: Buck's Harbor, Maine
Country: USA
Vessel Name: "Emily Anne"
Vessel Model: 2001 Island Gypsy 32 Europa (Hull #146)
Join Date: Sep 2008
Posts: 2,733
RE: Alternator Failing?

We have the same engine, same year, same problem last season except voltage would drop to 11 or so and low voltage alarm would come on. Eventually, even at higher rpms, the voltage would not go up. Our local Cummins mechanic disconnected the preheater plug on the port side of the engine and we have had no problems since. A little dark smoke on start up. Mechanic said 90% of the local lobster boats disconnected this item for the same reason. There is a workaround of putting a dash mounted momentary or on/off switch in the circuit if one wants to be able to use the preheater but, since we use the boat in the warm months, we haven't gotten around to that yet.
dwhatty is offline   Reply With Quote
Old 03-09-2010, 01:19 PM   #5
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
RE: Alternator Failing?

I assume that you are saying that the pre heater plug and the post heater plug are the same?
Doc is offline   Reply With Quote
Old 03-09-2010, 01:30 PM   #6
TF Site Team
 
dwhatty's Avatar
 
City: Home Port: Buck's Harbor, Maine
Country: USA
Vessel Name: "Emily Anne"
Vessel Model: 2001 Island Gypsy 32 Europa (Hull #146)
Join Date: Sep 2008
Posts: 2,733
RE: Alternator Failing?

Quote:
Doc wrote:

I assume that you are saying that the pre heater plug and the post heater plug are the same?
Dunno about that. I could show you a pic of the plug if I could get my bleeping camera to work.
dwhatty is offline   Reply With Quote
Old 03-09-2010, 02:39 PM   #7
Guru
 
Codger2's Avatar
 
City: San Diego
Country: US
Vessel Name: "Sandpiper"
Vessel Model: 2006 42' Ocean Alexander Sedan
Join Date: Oct 2007
Posts: 5,421
RE: Alternator Failing?

Doc:

I also have a 330B and mine has been doing as you describe for 3 years. At cruise (2000) there is no fluctuation.
Codger2 is offline   Reply With Quote
Old 03-09-2010, 03:06 PM   #8
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
RE: Alternator Failing?

Dwhatty *has a bleeping camera. Mine doesn't bleep it's Japaneese it says CRICK

SD
skipperdude is offline   Reply With Quote
Old 03-09-2010, 06:43 PM   #9
TF Site Team
 
dwhatty's Avatar
 
City: Home Port: Buck's Harbor, Maine
Country: USA
Vessel Name: "Emily Anne"
Vessel Model: 2001 Island Gypsy 32 Europa (Hull #146)
Join Date: Sep 2008
Posts: 2,733
RE: Alternator Failing?

Quote:
skipperdude wrote:

Dwhatty *has a bleeping camera. Mine doesn't bleep it's Japaneese it says CRICK

SD
Mine's Japanese as well and it neither bleeps nor cricks at the moment.

*
dwhatty is offline   Reply With Quote
Old 03-15-2010, 10:46 AM   #10
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 5,633
RE: Alternator Failing?

They are practically putting cameras in Cracker Jacks as a prize they are so cheap these days....go getchya a new one!!!!
Baker is offline   Reply With Quote
Old 03-16-2010, 06:38 PM   #11
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
RE: Alternator Failing?

Rupert the alternator repairman said to get my (_,_) down there and check the belt and the tensioner before pulling the alternator. Tomorrow maybe.
Doc is offline   Reply With Quote
Old 03-20-2010, 01:49 PM   #12
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 5,633
RE: Alternator Failing?

Generally, your first clue that it is the belt is that there is a lot of dust in the vicinity....a belt that is slipping will dust things up something fierce.
Baker is offline   Reply With Quote
Old 03-21-2010, 08:01 AM   #13
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
RE: Alternator Failing?

I pulled it yesterday and took it to Rupert. He wasn't there but his son said that it would be ready Monday.

There was no dust, the tensioner ran smooth and true with a new belt. I load tested the batteries and they didn't quiver. That's about all I know to do.
Doc is offline   Reply With Quote
Old 03-23-2010, 01:18 PM   #14
Doc
Guru
 
Doc's Avatar
 
Join Date: Oct 2007
Posts: 508
RE: Alternator Failing?

Rupert gave it back to me yesterday and I put it on today. Still does almost the same thing so I guess there was nothing wrong with it. He said that it will show lower volts at idle so as to not load the engine until rpm's are increased.

It got a good corrsion cleaning and a new regulator anyway.

Moral of story...if it ain't broke...
__________________

Doc is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
alternator problem? septembre Electrical and Electronics & Navigation 7 08-11-2011 02:43 PM
LF Alternator Swap? Dixie Life Electrical and Electronics & Navigation 11 03-26-2011 01:46 AM
Alternator awpptdt Power Systems 2 12-15-2010 05:50 PM
Alternator Source FF Electrical and Electronics & Navigation 0 08-06-2009 04:17 AM
Another Alternator Question Max Simmons Electrical and Electronics & Navigation 12 05-18-2009 10:38 AM




All times are GMT -5. The time now is 08:11 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012