Dodge Repair: headlites shuting down

Question
1988Dodge2500series4x4 automatic 5.9 liter
Headlights are shuting off on high and low beams can you give me an idea where i should start and complete diagnoses .your help will b appreciated

Answer
Hi Jeffrey,
Unfortunately my collection of manuals for trucks if limited to the years 2004-2007.
Take a look at your high/low beam switch as it may have a loose connection or oxidized contacts inside. You could spray some contact cleaner into the switch through a hole or crack.  Another possibility is a fuse that brings power to that switch is cracked so goes on and off by itself. Finally there is usually a single common ground wire from all the headlamp bulbs (black in color) and that may be loose at its connection to the nearby bodywork. So look for black wire at any of the bulb plugs and trace it to find the ground point.
Please read the PS below and respond to it.
Thanks,
Roland