Quick question: boats running pull the positive cable and the boat should keep running right? If it dies is the alternator the only culprit?
Thanks

You having a charging problem?

Only seeing 12v on the gauge engine running, got the battery advice from a buddy. Alternator is a single wire Delco

A single wire Delco uses itself to excite,  so no battery,  no charge.

Just bring it to a genny  shop and have it checked.

There isn't much in there. 

A set of brushes,  a regulator,  two diode trio's and bearings.

The diode trio's are easy to check with an ohmmeter. The brushes are self explanatory and the regulator is super cheap.

Are you sure it's a one wire? In other words,  did it used to work?  You would be shocked how often this gets overlooked.

GT

GT if I put the trusty old multimeter on the back of the alternator should I be seeing voltage?

GT if I put the trusty old multimeter on the back of the alternator should I be seeing voltage?

 Large wire from the post on the back of the alt goes to the battery (constant 12 volts).  So yes, if the battery is hooked up you should see voltage, running or not.  If no voltage is showing at the battery post on the alt, check your wiring, look for a circuit breaker, fuse, or bad wire.  But, make sure your multimeter is grounded well when checking. Seen many times people try to check things and claim no power because they weren't checking from a good ground.

 Did you change ANYTHING electrically prior to noticing the alt wasn't charging (new starter, dash wiring, etc) ?

 One volt with the battery hooked up ?   That wire on the back of the alt should show full battery voltage at all times. Check your wiring/connections. The alt can not charge the battery if that wire does not have a good connection directly to the battery (constant 12 volts).

Thanks gents I actually did identify a wiring issue I had to deal with, this discussion actually prompted me to check things out so thanks

Alternator rebuilt wiring good to go, only issue now is I'm seeing 15v on the gauge??

What do you see with a DVOM?

14.5vdc is considered perfect, I'm thinking you're good.

GT

Thanks gents