I have an 84 272 and the gauges go crazy when I turn anything electrical on IE blower, lights, trim,bilge pump any thing that is originally installed on the dash!!! Anything hooked direct to the battery does not affect the dash!!! Has Anyone experienced this problem?

Power feed problem to dash, most likely? Corroded connectors can't supply enough current -> voltage drops and gauges start acting up?

Wiring for sure. Loose, corroded. Any number of variables. If it is all gauges everytime at least you can start with Maine power and ground to terminal block.

That's what I was thinking also!! Would it be easiest to jus run new power to batter switch and ground wire instead of trying to chase the problem down? And where is the distribution block grounded? Back to both engines? I assume?

Start with connections first. Sometimes you gotta cut wire back an inch or so because exposed part a too corroded. Try cleaning all connections real good. Hook a meter up to to power and terminal block and check for voltage drop. Lots of trouble shooting to do before pulling new wires.

However you could string out a "temp" power wire direct from batter to terminal block and if that solves the problem then you know it's in the power wire. That would be the quickest test.

I might try that tonight see if that solves the problem!! Thanks