are the 9 and 10 pin wiring plugs the same?

The 10th pin is for the alarm.

i noticed the harness on the motor i just got #4 pin is a big one so out of the 9 pins it has 3 big ones. my other harnes the #4 is a small pin and out of the 10 pins it only has 2 bigger ones

i am looking at a couple of broken wires that have been routed around the plug and had a thought...trailer connector!!!

the first one is the one on the motor and the second one im sure is what i need. I dont have my boat here to check to be 100% sure
can you sleeve the #4 big one to accept a smaller pin?

The third large pin is for an amp meter. Boat used to run amp meters now they run volt meters. The old harness will have a 10 gauge red,black and orange wire. The orange is for the amp meter.

ok that explains it as the orange wire is taped off in the altenator harness. so i should be good to go and plug into it then?

I'm pretty sure the rest of the pin out is the same.

well im gonna plug it in and hope for the best i guess