First, thanks hatzie for compiling those manuals. I’ve saved them and refer to them often. You’re a good egg, brother!
I’ve found one Corvette Cruise Master write-up here:
http://www.splashedpaint.com/cameron...iseControl.pdf
Not sure if that’s what you’re referring to. I will most likely give tearing down the transducer a try. Like you said, can’t make it worse. I wish I could find more photos/info specific to the transducer. Your manuals and the training textbook say “replace” rather than service. Since I can’t replace, I’ll give servicing a try.
My system doesn’t have power at the moment. The attached pic shows a few wires that are disconnected near the fuse block. The blue connector has a blue plug, but looks like it comes out of a plug that’s in the fuse block. No idea what the orange wire is. Everything else on the truck seems to work...