200hp Merc voltage issue.

[Trampsinger]

I have a 2001 carbed outboard. I've noticed it wasn't charging. I checked the battery and then I checked the 3 20A fuses on the motor. The middle fuse was popped. I replaced it and within 15 seconds it popped. Nothing is on. The boat is off and in the driveway and the master power switch is off. That switch disconnects all accessories from the battery. Any idea where I can start trouble shooting or maybe someone has seen this before. Boat runs fine just doesnt charge.
Thanks guys I appreciate it.

 

[Trampsinger]

OK ive disconnected everything from the battery except the two large positive and negative cables. pops everytime.
Does this mean my voltage regulator is shorted?

 

[sam am I]

Could be, disconnect the red bullet connector's coming from the reg/s now. Shouldn't blow fuse anymore if it's the reg's that are shorted..

 

[Dukedog]

Does your trim work when its popped?