Hello and thank you for trusting Just Answer with your question.
How long has this problem been going on?
just last night
Both dropped out at the same time?
The most likely failure is burned out bulbs. What happens is that most people don't notice when one goes out, but they certainly do when both go out. Have you checked the bulbs?
What tools and skills do you have?
yes the light for hight beam does not come on but the hight beam is all that works
How technical are you?
all tools skills do most work myself and have book for this truck
yes i check the bulbs
Ok, the way the circuit works is that the headlight switch turns on the headlight relay, then the headlight switch grounds the circuits to turn on either high or low beam.
Go go to the left headlight, and check the voltage (with the headlights on low) at the red/blue, the blue/black and the red/yellow wires and let me know what you find.