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

Reply
 
Thread Tools Display Modes
  #1  
Old 09-24-2004, 10:43 AM
BrianS BrianS is offline
TT Enthusiast
 
Join Date: Jul 2004
Boat: '08 X14 & '93 Prostar 190
Location: Dayton, OH
Posts: 119
Possible alternator problem?

I have a '93 Prostar 190 with 582 hours on it. The boat starts and runs fine, but when running the voltmeter reads less than 13 volts. I thought it should read 14.4V if the alternator is charging? I'm pretty sure the guage is working because the voltage dips when starting and if I turn on the nav lights or blower.

I purchased the boat this spring and it has been like this since I've owned it, about 70 hours. It has never failed to start or had any other problems.

The reason I bring this up is that I was out after dark for a while last night and had the lights on for a while. The voltmeter seemed to be reading a little lower than normal and it took an extra second or two of cranking to start.

What is the best way to test the alternator to see if it is bad? What is the typical lifespan of an alternator?
Reply With Quote
  #2  
Old 09-24-2004, 11:02 AM
NeilM's Avatar
NeilM NeilM is offline
MC Devotee
 
Join Date: Jul 2004
Boat: 2002 MariStar 210VRS 330hp Tower, Ballast, Bimini, 400w Clarion
Location: Calgary, Alberta
Posts: 1,008
Brian,

The BEST way to test an alternator is to take it to an alternator rebuild shop and have them do it.
If your voltage stays at 13 or more, though, I wouldn't be worrying too much about it.

As far as lifespan goes, it's virtually impossible to say on a boat.. Moisture, not hours, is your biggest enemy. I've seen alternators on one-year old boats all corroded and starting to fail; on the other hand, I know of I/O's with over 15 years on the original alternator...
__________________
2002 MariStar 210 VRS 330hp, Tower, Perfect Pass Stargazer, Bimini, Triple KGB Ballast, 400w Clarion XMD3, Bennett X-14 Wake Plate, 1000+ hours and still running great!

Life is not a journey to the grave with the intention of arriving safely in a pristine, well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming "-- WOW--What a Ride!"
Reply With Quote
  #3  
Old 09-24-2004, 11:18 AM
Footin's Avatar
Footin Footin is offline
MC Maniac
 
Join Date: Aug 2004
Boat: 2007 Maristar 200VRS X2
Location: Columbus,OH/Monticello,KY
Posts: 4,634
Removing and taking in is the best way, but if you want to do a quick check, put a multimeter on the battery when the boat is NOT running, this reading should be around 12.55 to 12.70 volts. Now start the boat and take another reading, this should read 13.8 to 14.6 volts.
Reply With Quote
  #4  
Old 09-24-2004, 11:19 AM
BrianS BrianS is offline
TT Enthusiast
 
Join Date: Jul 2004
Boat: '08 X14 & '93 Prostar 190
Location: Dayton, OH
Posts: 119
I suppose that is what concerns me, I've never seen the voltmeter read at or above 13 volts. However, the boat starts and runs fine.

Is pulling it the only way to test it? I was hoping there was an easier way.

Thanks for the reply.

Edit: Didn't see Footin's reply. I'll take the multimeter with me next time I'm out. Thanks.
Reply With Quote
  #5  
Old 09-24-2004, 11:21 AM
Footin's Avatar
Footin Footin is offline
MC Maniac
 
Join Date: Aug 2004
Boat: 2007 Maristar 200VRS X2
Location: Columbus,OH/Monticello,KY
Posts: 4,634
Don't always trust the gauge. I had a 87 Prostar 190 that read 10 volts when not running; however the multimeter showed 12.65.
Reply With Quote
  #6  
Old 09-24-2004, 12:00 PM
lakes Rick's Avatar
lakes Rick lakes Rick is offline
MC Devotee
 
Join Date: Jul 2004
Boat: MC Maristar 225 VRS 1994 350TBI
Location: Eugene, Oregon
Posts: 1,581
Brian, my 94 reads the same, around 13 volts.. I honestly do not think the stock gauges are the best..
Reply With Quote
  #7  
Old 09-24-2004, 02:48 PM
BrianS BrianS is offline
TT Enthusiast
 
Join Date: Jul 2004
Boat: '08 X14 & '93 Prostar 190
Location: Dayton, OH
Posts: 119
Thanks guys, it's reassuring to know that the guage could be the culprit.

I'll check the voltages with a multimeter next time out to make sure.
Reply With Quote
  #8  
Old 09-24-2004, 07:40 PM
Fan
Guest
 
Posts: n/a
All great information guys. Keep in mind too that if the battery is fully charged (12.68 v) the alternator will be not be putting out as much voltage. If you are reading 13.5 volts or less, turn on some lights and crank up that stereo then see what the old multimeter says. Should read 14.3 (+/- for the inaccuracy of the multimeter).
Reply With Quote
  #9  
Old 09-24-2004, 07:49 PM
SkySkiSpokane's Avatar
SkySkiSpokane SkySkiSpokane is offline
TT Enthusiast
 
Join Date: Sep 2004
Boat: '95 Prostar 205 LT1
Location: Spokane WA
Posts: 221
95 PS205 LT1, My gauge sucks. It is even worse than yours. The alternator is only one year old and usually reads between 10 and 12. I put a multimeter on it and it reads just over 13.5 with heater and shower running. I hate not having one that I can rely on!!
__________________
Dave
'95 ProStar 205 LT1
Reply With Quote
  #10  
Old 09-24-2004, 08:16 PM
JimN's Avatar
JimN JimN is offline
MC Master Poster
 
Join Date: Jul 2004
Posts: 11,674
If you want to know how far off the gauge is and why, neasure the resistance from the ground on the gauge to the battery negative post, not battery neg cable. Clean the terminals after you measure it, then re-measure. If you see the voltage go up immediately after cleaning the terminals, you then know that they need to be cleaned more often. If it doesn't change and you see more than 1-1.5 ohms from the gauge neg to the battery neg post, check any connections between the two positions.

Brian- removing two wires and three bolts so the alternator can be taken in for testing hardly sounds like a big chore.
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 07:25 PM.