I have a 2001 Bayliner with a 5.0 Mercruiser inboard engine, its basically a Chevy 305 which most everyone knows. It wasn't turning over when I turned the key except every fourth time so I figured the solenoid was going out. In order to replace it I had to buy a new starter and solenoid as they are one unit on this motor. It has two large terminals for the main battery connection and two smaller ones which I assume come from the key and tell the solenoid to engage when the key is turned. I installed all the wires the way I remembered them being and when I turned the battery kill switch back on, the starter ran full blast. The solenoid wasn't engaged so it wasn't turning the flywheel, it was just spinning inside the housing. I ended up unattaching all the wires but the hot wire and it still did this. Only when taking off the red wire did it stop. It really doesn't seem like I installed the two battery wires backwards because of the position they are in but I have no idea why this is happening. Anyone have any ideas? I am flummoxed.