We were out in our 1999 Sundancer...

[krobel]

We were out in our 1999 Sundancer 450 and gages were working fine. Stopped for the night and on startup the voltage gages were not working. Are they on a fuse or a circuit breaker? Engines running fine but hard to imagine both alternators or both gages crap out simultaneously. 

[wingless]

The dash gauges are fed from the engines through the boat wiring.

The symptoms indicate a wiring / connection problem.

[Diduwanna]

follow the wires to the fire wall block and clean the pull off contacts. Then spray them with a protective from moisture.