90 Dynasty headlights go out

After 20 minutes of driving the headlight go out and become very intermittent flashing on and off. Replaced dimmer switch and headlight swich twice checked all fuses and breakers.

Thanks

After 20 minutes of driving the headlight go out and become very intermittent flashing on and off. Replaced dimmer switch and headlight swich twice checked all fuses and breakers.

Thanks
if you have tilt steering wheel,when you tilt it down it may be the problem
good luck