Problem with my 98 F-150 and the headlights/interior lights. When I turn on the headlights, all instrument and heater control lights get real dim, the dome lights will come on with no problems.

Anyone have any clue as to what would cause this?
Thanks

Jason

 

It should just be a matter of adjusting the dash lights using the graduated wheel near the headlight switch. this is the switch that will also turn on the interior dome if you turn it far enough.

 

Do you mean accessory lights or instrument lights?

It's normal for the accessory lights(most notably the lighting for the clock/radio) to dim when the headlights are turned on.

As for the instrument panel lights... follow TRL's advice

 

The graduated wheel does nothing. When you turn on the headlights, all instrument lights and lights on heater/ac controls do not come on. The only lights that work on the interior are the dome lights.