headlight problem

first off my truck is a 1994 c1500 with a 305 and my head lights seem to go on and off at random times like when i would it a bump. i checked the grounds and i was looking for ny help as to what else i need to look at to figure this out. as of right now i can only drive it durring the day whih sucks. any help would be much appriciated.
thanks
mike

It could be the headlight switch and or the dimmer switch.

the switch is only about 5 years old. also where is the dimmer switch?

Dimmer switch is part of turn signal lever. Before tearing it apart, check your connectors at the headlights themselves. One bad connection at the bulb can cause similar symptoms. Look for overheating, melting, corrosion after removing the bulb connector.