Never removed the steering wheel before. That sounds like a brutal task. I think the first approach should be to disconnect at the inlet of the damper and blow through that and out the line to the pitot tube. Will disconnect the pitot prior to inducing air.
I don't have storage boxes in the back, only a single panel that raises upward on a hinge for battery access. The battery sits in a tray. The only access is when the rear seat is out, there is a gap between three and four inches you can see under. If I remember correctly, the floor carpet goes up the back under there. No idea how to gain access to anything under the floor except in the middle where a floor panel lifts for rudder lube etc.
Plan to get the boat out of storage this weekend so I'll study it. Will take pictures if I don't see an easy way in.
Thanks for your suggestions. Together, we'll figure this out. Really would like to have it working properly again.
As my dealer says, "Remember, it's a MasterCraft. It's always something simple".