I assume we are talking about the Bassa. As was questioned a couple of posts ago, the Bassa does not have an electronic compass built in. In that case, we would be referring to the Neutral Light. Regarding the low fuel light, obviously it should not come on when the tank is full. Out of curiosity, when it came on, was that the first and only time it lit up? Also note that when it is working properly, it will begin to glow dimly, coming on and off and then gradually getting brighter until it pretty much stays on, glowing brightly. It starts lighting up with about 1.6 gallons left in the tank. (Just a point of reference so you know what should be going on.)
John Henry