fuel and spedo guage not workin

What model motor, what type gauge, year, command link or +. GPS speed or pitot? Not enough detail to guess

Adding onto what Bill said, the reason for those questions is that any number of brands of engines could be on the boat and then each brand of engine can have multiple styles/brands of gauges.

Ditto to what has been said, adding the question; " Do the gauges power up and go through the initial self test?"

When you say that the speedo stopped working do you mean the gauge is blank or do you mean the speed displayed is incorrect. If th later, you probably have a pitot tube issue on the lower unit

Same question for fuel gauge. Is the display blank or is the level displayed wrong. If so , first place to look is the sender signal from the tank

My speedo also stop working recently on our Overnighter. It was the pitot on the rear had broken. Just recently purchased a new one. It’s an easy fix, many videos online . Our fuel gauge also was intermittently working. After inspecting the back of the gauge the prongs had corroded . Cleaned up the wires and installed a new gauge. No more problem. Hope this helps.