While driving my 2001 Dodge Ram truck the "check gauges" light comes on periodically and the temperature gauge shoots all the way up. After a few seconds the temp gauge returns to normal operating range and the warning light disappears. Occasionally the fuel gauge will register as empty and the low gas light comes on--even though the tank has plenty of gas. In this case I must turn off the engine and restart it to return things to normal.

Test the alternator--it sounds like the voltage regulator/brush assembly needs replacing, which is easy to do yourself. I suspect the brushes have worn down too far. Most auto parts stores will test alternators for free.