Gauges will not register in the event of total power loss but that's the least of your worries. Technically fuel gauges can be deferred if non-functioning on the ground. The pilot would "stick" the tanks and measure how much fuel is loaded. He can then calculate his fuel burn in Pounds Per Hour (PPH) and estimate amount of fuel in a tank. Aircraft usually have more fuel than required to make a specific route, in case they have to divert to other airports.
Fuel, coolant, voltage
Fuel, coolant, voltage
Fuel, coolant, voltage
Bad electrical connections.
These will be the coolant temperature gauge, oil pressure gauge, and battery voltage gauge.
Check fuse labeled Gauges.
The coldness
Not unless you are up in the cockpit of the plane. A heavy duty magnet could cause gauges to read incorrectly.
Mechanical drive for the speedometer only.
Could be the sending unit or a problem with the wiring if electrical.
Yes, all circuits are protected by a fuse.
They are called gauges. Perhaps I don't understand the question. There is a fuel gauge, which tells you how much fuel you have, or an electrical gauge, or one that gauges speed. I guess depending on the gauge there is a different name. So your speed gauge is your speedometer. Your RPM gauge is the tachometer, and so on.