I suspect either a faulty ground circuit, or a much easier fix, faulty bulb/bulbs. You might be surprised the havoc a grounded out bulb will cause an electrical system.
Headlights,interior lights stop working.checked all fuses. I would suspect the headlight switch and/or the electrical connection at the headlight switch is faulty.
Check the fuses. If they are good then you will have to replace the headlight switch.
Bad headlight switch.
You more than likely need to replace the headlight switch. Lights not going out when turned off is a symptom of a bad headlight switch.
Bulbs? Fuses? Relay? Dimmer switch? Headlight switch?
The headlights are a separate circuit from the others. Check the bulbs, headlight switch, Hi/Low beam switch and depending what year you have check the fuses.
Parking and dash lights also on this circuit - do they work? Check fuses Could also be a bad headlight switch
The headlights do not have a fuse. There is a circuit breaker built into the headlight switch.
Headlight switch.
There is no fuse for the headlights in that truck. The circuit is protected by a circuit breaker located inside the headlight switch.
The Headlight switch is where the dash receives it's power from.
Check your headlight switch. Sometimes the switch goes bad and the dash lights won't light. Replace the switch for the fix.