Alternator?

I have a 1991 Regal Valanti and after a fairly lengthy saturday cruise, my boat will not start the next day unless I charge the battery the night before. I have ran a test on the alternator and it seems like it is charging although I do not have a digital charger to be more accurate. Any of you guys have a suggestion?

Re: Alternator?

Ayuh,.......

If the Altenator is Working,..... There'll be about 13.6Volts when running.....

If the Battery is Good,.... It'll show about 12Volts when Not running.......

Re: Alternator?

If you don't have a voltmeter handy;

After running a while, place your hand on the alternator. If it's working, it will be warm, around 120? F.

Re: Alternator?

you can buy a voltmeter from radio shack for less than 20 dollars, make sure its digital and for voltage tests you dont even have to worry about lead polarity.
the hand trick is very unreliable and for gods sake DO NOT dissconect a battery cable while the engine is running. most modern charging and ign systems tend to fail due to the voltage spikes.
alenator output is simple to test,especially the single wire ones.
others you will need to check for sense voltage,usually red or pink,excite voltage,normally purple and output voltage,normally orange or red 10 Ga.
check battery voltage with engine off,start engine and test the wires at the altenator, you should see 1.5-2.5V higher than with engine off.
anymore its really not worth messing with repairing an altenator, just replace it.

Re: Alternator?

Maybe your battery is old and not holding a charge?

Re: Alternator?

Thanks Guys,

I took the battery to a local auto parts store and the guy tested it and said it was ok. Then I decided to get another opinion and took it to two other auto parts stores including the one I purchased it from (Walmart). Found out that the battery was bad (only 15 months old) but Walmart replaced it for a fee they called partially used. I think if this happens again I will buy a really good dual cycle battery, any suggestions? By the way my engine is a 3.0L mercruiser with just a cd player and depth finder.

Re: Alternator?

As far as batteries, the reason batteries cost more is the plates internally used to make them. The more expensive batteries usually have more and higher quality plates. That's why they have a better life expectancy. Also when your boat is stored, remove the battery and once a month put it on a trickle charge to keep the charge up.