RE: 1957 chevy truck

My headlights are flashing after being on for about 30 seconds.

I have checked all the connections and wires from the headlight switch thru the dimmer switch to the driver's side headlight on thru to the passenger side headlight. I pulled all the connections and applied dielectric grease to the terminals.

One note...If I unplug the passenger side headlight connection, the driver's side headlight stays on without flashing. IDEAS?!?!?