PO of my f150 told me that sometimes he would come out in morning and have to jump his battery. even his new ones....so he would click off the dimmer switch next to headlight switch. well it seems that its because the interior lights randomly turn themselves on when driving or when not. so i picked up another headlight switch assembly from junkyard (actually looks cleaner than mine) and installed.

needless to say it came back. any ideas on what could be causing it? i do not believe its a door sensor, atleast the open door icon doesnt turn on. i just wait it out to turn off dimmer for a while but it is annoying especially at night and i have no lit lights or radio.

 

Check all of your relays is all I can think of at this moment

 

Dumb question. How do I test a relay?

 

Just swap it with the relay for something you know is working and then test feat use that you swapped with.