2005 Nautique 196 Guages

Just purchased an 05 196, previous boat 1989 Nautique 2001 model. Obviously the new boat is more complex. I have 2 gauges on the right hand side that are not working, volts and Temperature. The odd part is that when the dash lights are on these 2 gauges don't even light up. Just wondering if this could be a simple electrical connection or fuse problem. Stuck my head under the dash but didn't see any way to get at the gauges, will I have to take the whole dash off to get to them? And I'm afraid to ask what that might entail or if I would need to take it to a mechanic to have it done?
Suggestions?, I am fairly competent at mechanical issues, on old boat I would do oil changes, winterize, replace thermostat, impeller, plugs, points, adjust through hull fitting, etc   Thanks

What trim level is the boat, Team - Limited or Signature?
If you have digital gauges (Team or Limited) check your gateway box connections

Do you have a key or a keypad? That will help me determine what trim level and gauges you have.

Then you have digital gauges, check the gateway box, should be in the trunk, possibly attached to the liftring ring threaded rod. There will be a couple pitot lines for the speedos and then several various sized shaped plugs for the gauges, pp, etc.
Make sure all the plugs are clean, plugged in and pushed in tight.
Also a good idea at winterizing the pull the pitot tubes, they are supposed to self drain but if do not will freeze and back up water into the gateway and smoke the circuit board.

          
I am not a whiz on the computer, tried uploading photos of boat and dash. boat went into storage today so any repairs will have to wait until spring.

Back to gauges. Put boat in a few weeks ago, checked gateway box, all connections seem tight. But before checking I noticed that the Temp guage was working, but not consistently. Seems to work ok then the next time out it doesn't, the volt guage is still non operational all the time. Ideas?