Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Electrical

Reply
 
Thread Tools Display Modes
  #1  
Old 07-06-2014, 03:56 PM
alfie623's Avatar
alfie623 alfie623 is offline
TT Enthusiast
 
Join Date: Jul 2013
Boat: Mastercraft, Maristar, 1999, 330 LTR
Location: New York
Posts: 110
Is new amp killing my alternator?

Something is not right in my boat and I can't seem to figure out what. Last summer the boat ran fine electrically. Over the winter I replaced the non-functioning heater motor and added a 400 watt amp to the stereo. Almost immediately my alternator stopped working and I replaced it with a new alternator and it appears as thought that one has stopped working too.

Is it possible that the draw from the amp is over working the alternator? If so, how can I figure out what alternator capacity to look for? I haven't had the battery tested but I can charge it and it will take a charge fine and then I can use the boat for a day off of that charge.

I figured I would probe here before I started doing a bunch of research and trying to sort through mountains of inaccurate information.
__________________
'99 Maristar 210 VRS with 330 LTR
Reply With Quote
  #2  
Old 07-06-2014, 09:27 PM
MLA MLA is offline
TT Enthusiast
 
Join Date: May 2012
Boat: pontoon
Location: Lake Wylie Area
Posts: 428
Give us some more details:

what amp brand/model?
One or two batteries?
How is the amp wired, as in where are its power cables connected?
What and how many speakers is the amp driving?

My gut says no, the addition of the amp is not the cause of the alternators death.
Reply With Quote
  #3  
Old 07-06-2014, 11:29 PM
alfie623's Avatar
alfie623 alfie623 is offline
TT Enthusiast
 
Join Date: Jul 2013
Boat: Mastercraft, Maristar, 1999, 330 LTR
Location: New York
Posts: 110
I have a JL M400/4 amp.
One battery.
Amp is wired directly to the threaded posts on the battery. The positive lead passes through a fuse block.
The amp is driving 4 JL M series 6-1/2" Coaxial speakers.
__________________
'99 Maristar 210 VRS with 330 LTR
Reply With Quote
  #4  
Old 07-07-2014, 09:50 AM
curver900 curver900 is offline
TT Enthusiast
 
Join Date: Aug 2013
Boat: Mastercraft, prostar 2001 205v
Location: midwest
Posts: 444
added an amp... do you have other amps? if so what are they? a 400W amp would not cause that large of a draw that a 51amp alt couldn't handle.
Reply With Quote
  #5  
Old 07-07-2014, 10:12 AM
alfie623's Avatar
alfie623 alfie623 is offline
TT Enthusiast
 
Join Date: Jul 2013
Boat: Mastercraft, Maristar, 1999, 330 LTR
Location: New York
Posts: 110
I don't have any other amps. The only other electrical draw would be the heater, blower, bilge, shower pump and lights and I haven't used most of those items. The only thing I used really was the heater and the blower.
__________________
'99 Maristar 210 VRS with 330 LTR
Reply With Quote
  #6  
Old 07-07-2014, 10:34 AM
David Analog's Avatar
David Analog David Analog is offline
TT Enthusiast
 
Join Date: Sep 2013
Boat: N/A
Location: Texas
Posts: 247
That amplifier into a 4-ohm load on all channels is likely to pull only 20 amps or less at non-distorting full power. Your alternator can easily handle that additional load.
Now a bad battery can create an inordinate load on an alternator leading to failure. But if you are running most of the day off battery power and independent of the alternator it wouldn't appear you have a bad battery. But battery status is easy to check so that is still a good place to start.
Do you see an elevation in your voltage reading on the dash volt gauge when you start the motor and give it some rpm, say at 2000 rpm?
Reply With Quote
  #7  
Old 07-07-2014, 10:53 AM
alfie623's Avatar
alfie623 alfie623 is offline
TT Enthusiast
 
Join Date: Jul 2013
Boat: Mastercraft, Maristar, 1999, 330 LTR
Location: New York
Posts: 110
I don't see an elevation in voltage, just a drop. I run a trickle charger on the battery all week and when I use the boat I see the voltage drop from 13 to 12 (and less) as I use the boat.

Today I'm going to pull the alternator and the battery and take them to the electrical shop I bought the alternator from for testing.


Sent from my iPhone using Tapatalk
__________________
'99 Maristar 210 VRS with 330 LTR
Reply With Quote
  #8  
Old 07-07-2014, 11:15 AM
David Analog's Avatar
David Analog David Analog is offline
TT Enthusiast
 
Join Date: Sep 2013
Boat: N/A
Location: Texas
Posts: 247
If you are running exclusively on battery power a good battery may not be good for very long.
Reply With Quote
  #9  
Old 07-07-2014, 12:18 PM
alfie623's Avatar
alfie623 alfie623 is offline
TT Enthusiast
 
Join Date: Jul 2013
Boat: Mastercraft, Maristar, 1999, 330 LTR
Location: New York
Posts: 110
As far as I can tell. If the alternator was working I would think that I would see 14 volts on the gauge. When I installed the new alternator I saw that for the first ride in the boat but that was it. On the second ride I was right back to less then 13 volts and dropping.

I'm going to pull the batter and alternator right now and run them to the shop and see what we find.
__________________
'99 Maristar 210 VRS with 330 LTR
Reply With Quote
  #10  
Old 07-07-2014, 01:27 PM
TresRiver205's Avatar
TresRiver205 TresRiver205 is offline
TT Regular
 
Join Date: Oct 2013
Boat: 95 Prostar 205
Location: PA
Posts: 51
Back in college I had my alternator fail. I went and got a rebuilt one from the parts store. It lasted a few days and failed. I went all over the wiring trying to find what was killing the alternator. I asked my dad about it and he just said some choice words about the quality of rebuilt parts. We returned the rebuilt failed alternator and went to a junkyard owned by a friend of his and got a used alternator. That one worked as long as I had the car. So the replacement could have failed on it's own accord.
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


All times are GMT -4. The time now is 06:43 PM.