Thought it was an ignition switch

[VolunteerBoater22]

Boat wouldn’t start so I replaced the starter solenoid. It then fired up and worked the next time out. But, the problem has returned. I replaced the ignition switch and it’s still doing the same thing.

I have power to the instruments because the battery gauge comes on when I turn the key to on. But when I turn the ignition it won’t crank up. We started it last time crossing a screwdriver over the starter.

Edit: I/O

Any thoughts?

 

[Scott Danforth]

start by cleaning the battery cable connections. every one of them, including the ground and the connection of the starter to the block

you dont state if this is an outboard or an inboard

 

[Chris1956]

A lot of MerCruisers have a slave solenoid on the block, along with a starter solenoid on the starter itself. You need to check both.....