I know this may not help but I wanted to share a similar situation I was going through, my 03 3.0 would blow it's key switch fuse the second I turned key to power, tried to start, or sometimes a few seconds after getting running. It ended up being the shift interrupt wire smashed in between the...
Did you end up doing your bellows and or gimbal yet? I have an 03 bayliner 185 with a 3.0, I've only owned for 3 years and I've done a lot of engine and lower maintenance but nothing on the bellows or Bell housing yet. I'm guessing it's all original so probably time. Watching and reading as much...