Ok so i'm going on a trip next weekend to Millerton and was geting boat ready and trying to chase down battery warning buzzer gremlin, which i think i fixed by redoing/clean the ignition connections and sealed with liquid electrical tape, I also was trying to figure out why my rpm gauge is flittering around sometimes but mostly is pegged in a position between 1k and 7k. However the motor and everything is running fine, all connections to gauge are tight, so i'm ordering a new gauge, but won't be able to change before the trip. I was tinkering around on the engine checking the electrical connections all around, and near the circuit breaker and starter relay there's a porcelain rectangle with wires going to the PCM cycloid and to the starter relay. Well i found part of that porcelain rectangle sitting on my transmission, so clearly it's broken and i have taken it off to take the marine mechanic tomorrow. Hopefully he has it in stock, other wise i'll have to put this one back on.
So my questions are:
What is this thing?
If i have to use the broken one can i use electrical tape to keep it together for the weekend?
Would this possibly be a cause of my tach gauge going coo coo?
I have posted pics of what i'm talking about
1994 Supra Sunsport
PCM 351 Windsor motor