Last min. Electrical issues :-( can I go boating today??

[IPhone pirate]

I was playing last min. Testing some things on the boat ('89 Bayliner Capri with I/o 302)

I was tooling with the volt meter and my battery reads 12.4 volts.... I start the boat, battery still reads 12.4 ...

My mind says bad alternator.... I remove the alt.. And take it to the local parts place for testing. They can not figure out how to wire it up sense it isn't in their books or on their computor screen, after fooling with it for a bit they get a " fail" reading....

I get back home and with the alt. off the boat I start it and once again it runs fine, 12.5 volts...

AND THEN I REMEMBER THE GOOD OL' BOY TRICK about pulling the neg. battery cable. I pull the cable and the motor dies....

I bolt the alt. back up and repeat the test, motor runs after neg. battery cable is removed...


What gives....?????? Help. I wanna boat today!!!

 

[MH Hawker]

Re: Last min. Electrical issues :-( can I go boating today??

at a idle it dosnt make much voltage , but it makes enough for it to run .

 

[IPhone pirate]

Re: Last min. Electrical issues :-( can I go boating today??

Are you thinking the higher rpms will kick up the charging amps as well? Hense charging the battery


Thanks for the reply by the way...

 

[MH Hawker]

Re: Last min. Electrical issues :-( can I go boating today??

yes if it is charging it will. thats. why that old trick works.

 

[IPhone pirate]

Re: Last min. Electrical issues :-( can I go boating today??

If anyone can help with this please chime in.

The boat runs under its own power at idle.. But the battery continues to show 12.5 volts



http://i981.photobucket.com/albums/ae300/mrwilliamisthe****/e9695eee.jpg

There are 4 leads on the back of the alt.. 2 off the starter solinoid, one being power output, he other going to acc.( electic choke )



The other two wires on the bottom go in to varing wire looms. All wires with exception of the Accy have 12.5 volts constant (. With key off )

Please give me a hand

 

[MH Hawker]

Re: Last min. Electrical issues :-( can I go boating today??

whats the voltage show at WOT while its in the water running. Not on muffs or in a drum.

 

[IPhone pirate]

Re: Last min. Electrical issues :-( can I go boating today??

I didn't test that yet ;( .... I spent the day diagnosing a problem that may not even exist....

 

[mark1905]

Re: Last min. Electrical issues :-( can I go boating today??

:facepalm:

Below 1200-1600, your alternator isn't going to kick in.

Rev motor to 1600 rpm. Put voltmeter directly on charging post of alternator. Read voltage. If it doesn't read at least 14v, you may have a problem. If you wasted an entire Sunday doing what should have taken you 3 minutes to do, I can only hope you had beer.

 

[bruceb58]

Re: Last min. Electrical issues :-( can I go boating today??

AND THEN I REMEMBER THE GOOD OL' BOY TRICK about pulling the neg. battery cable. I pull the cable and the motor dies....

And then you killed your regulator if it wasn't already dead. You never do that.

If your alternator is cutting in at higher RPMs than it used to, you probably have a bad regulator.