4x4 lights not lighting/blinking

Hello everyone. I just got a 1998 Ford Explorer Sport 4x4 and am noticing strange things with the 4x4 lights. When I swith to 4x4 from auto the lights do not go on. The transfer case does seem to engage and seems to work ok. Then I noticed that every once in a while the 4hi and 4lo lights on the cluster blink at me while I'm driving. If I switch to 4x4 and back it seems to solve the blinking lights but the cluster lights still do not come on. Could this be a sensor, switch problem, or hopefully not, a transfer case issue? Any help is appreciated. Thanks! Craig

Check the fuses, I know in the 2004's when the fuses are removed/blown, the 4x4 lights blink and the 4x4 will not engage.