View Full Version : Replace Alternator?

06-22-2008, 11:21 PM
A few days ago I went out on my '04 Mobius LSV and after about an hour and a half the electrical system started doing strange things. Perfect Pass went off and then came back, the bilge pump wouldn't work, then the boat started missing and acting strangely. Finally I stopped and turned it off and then it would not restart. Another helpful boater stopped and loaned me his battery to start the boat, but then when I unhooked the battery to give it back to him, the boat died. It would not run without the battery in it.
I came home, checked all of my connections, recharged the battery, and hoped that it was fixed. Today the same thing happened. So, I'm thinking that the alternator is not working. Anyone have other suggestions? If not, how hard is it to replace this alternator? I think that I have to remove the partition of the right side of the engine compartment to get at it. Any other tricks or problems that I should look out for?

06-23-2008, 09:39 AM
I have never chaged it or even looked at it. But it really sounds tlike the alternator. When you do get it off, take it in to your local Autozone, cheifs Auto, etc. Have them test it to see if everything is OK. Other than that, I really do not know. Sorry I couldn't be much more help. Good luck.

06-25-2008, 10:43 PM
The alternator came out easily, but none of the auto parts stores seem to be able to test it.

06-25-2008, 11:30 PM
I wouldn't really think too much about taking my alternator to an autoparts store. I would look up the local starter / alternator repair shop and take it there. However, first I would go to Lowes or Sears and get my hands on a 20 dollar multimeter. I would have everything shut down/off and record what the batter voltage was (it should be at least 12.7volts DC). Then I would crank the engine and then take the reading at the battery again. It should be higher (they charge in the 13 to 14 volt range), if the boat is fuel injected and the alternator is NOT working the voltage is going to be at least a volt less because you are running the fuel pump and injection system. If it is a carb motor it might not draw down much current so if it was close to the same intial reading then I would start turning on the lights and other accessories like the blower motor (this is getting the voltage regulator to kick in). If the voltage drops below what the intial battery reading was then I know that my system is not charging. I would then look for a proper ground on the alternator to the engine block and any loose connections to the alternator. I would purchase a battery post cleaner and make sure the battery post were cleaned. If this all failed then I would be removing the alternator and looking for that shop. All the while hoping it was the internal voltage regulator of the alternator (if it is designed this way, I am used to Bosch products not so much delco). These shops can rebuilt one at a fraction of the cost of a new one. And this is especially important for the starter since they turn the opposite direction of the auto kin the dealers want to charge you an arm and leg for one.

06-30-2008, 11:21 PM
Before I received Zegm's reply I found a place to test the alternator, and it was fine. To make a long story short, I had a pinhole in one of the hoses that runs up the back of the engine. When the boat was moving, water was spraying out of the hole and either causing the belt to slip or shorting out the alternator. So I guess the lesson is that if you have intermittent problems with your alternator, check your hoses.