Okay so this is my first time on the forums and I hope to god someone can help me out. Here’s the run down, I have a 2006 Ford F-150 at first i changed my oil and then I had a check engine light turn on so I disconnected my battery to reset it and that when my problem started. After I reconnected my battery my stereo started going all wack, by wack I mean the numbers and other buttons not lighting up and the screen staying very very dim. I eventually bought a new stereo and changed it out but no I have other problems. This is where it gets weird. When I have my truck on and turn in my headlights my stereo doesn’t turn off but just reads no signal and isn’t useable UNTIL i turn down my dimmer, but it works fine when my headlights are off andddd if I start my truck with my lights on it will never turn on so I have to turn my truck off then turn the lights off then restart it and my stereo then proceeds to work. I am completely stumped, if you have any suggestions I am all ears.

 

Sounds like your battery is toast or you have a very poor connection. Try cleaning the battery posts and the wire terminals really well. Ensure the batter connection is shiny metal good and then tight. If that doesn't clear it up then install a new battery. The gremlins shoiuld disappear. If they don't then into shopping for a new computer module for the truck.

 

Unplug the radio and see if it starts properly. Sounds like the aftermarket stereo's wiring was done wrong.