1991 300SE

my dash "light-bulb-out" warning light (the yellow icon with bulb and exclamation point in the center) comes on after crusing around awhile....and then somestimes it dosent come on at all...I look around the car when the warning lamp is on and don't see any lights out at night...any advice?




Lead
1991 300SE
1988 XJS V12
1976 Lancia Scorpion