I have an 89 272 with twin 454's. I just got around to getting it ready to go out for the first time and I knew the batteries were low. I started both of them two months ago. Had to let it sit because of military training. Anyway, I put the battery switch to all. I put an instant charger on the starboard battery and it cranked a few times. Cables on the charger got warm. I left it on there for a couple minutes. Now I have no power to the boat. Did I fry the batteries? I checked all the cables and all connections are tight/clean. Thanks for any advice and no smartass comments please.

Is there a regulator or something I may have fried, I also checked the fuses.

Did you check the main breaker where the harness plugs into????

If that hasn't tripped, try this article..

http://www.sterndrives.com/no_crank_condition.html

mercathrode thingy some times they fry and cause no power,

There are probably push to reset breakers on the dash as well. Did any trip? The ignition maybe?

Do you have no power to the entire boat? Is the boat not cranking at all? or is it not kicking over?
Did you check the fuse next to the starter Solenoid big red,

After checking all fuses, I thought I toasted the batteries but for some reason the instantcharger got toasted!? I put her on a trickle charge and a while later the twins came to life...so relieved. Thanks everyone!