97 maxum 1700 3.0 starter wiring question help

[mescam05]

i bought a project boat and the old starter was bad and already taken off. when i look at videos to refresh myself on replacing and wiring the videos i see they use 4 wires. specifically a purple/yellow wire. but when i look at my harness that leads to the starter i only see 3 wires. no purple/yellow wire. also i see a blue wire coming out of that same harness going to a bulb type thing on side of motor by the starter. guess my question is that is there a reason i dont have a purple/yellow wire in my harness or should it be there? also i dont know what that bulb thing is or what it does. sorry for any newbie stupidity. this is my 1st boat ve bought and started working on. thanks for any answers

[mmwjr]

Unfortunately the site software won’t let you post pictures until you have about 10 posts. I don’t know of a purple/yellow wire but there should be a red/purple and a yellow/red wires. Plus the heavy red battery wire. No clue what the bulb thing is unless it’s the oil pressure sender which has a light blue wire.