07 Ford F150 instrument light/radio help

[fasternu]

I have an 07 Ford F150 Supercrew, 5.4 V8, and last night when the headlights turned on, the radio shut off. Thought it was just a blown fuse, but when I turned the headlights off again, the radio started working again. Every time the instrument panel lights come on, the radio loses all power. As soon as the lights are turned off, the radio turns on like nothing ever happened. Is this a short somewhere, a fuse/relay issue, or a radio issue itself? Any help is appreciated!!! I hope somebody has had experience with this and can give some advice on where to look....

[fishinben351]

theres a wire coming out of the back of your radio to your dimmer switch i beleive its orange. The only thing i can think of is its shorting out somewhere on that switch to that wire. You can pop out that switch from the dash and look at the wires on the back see if anything looks melted. good luck

[fasternu]

Thaks for the input. I checked the ground connections behind the kickplates and found 3, all secure and clean. I then pulled the stereo out and checked the connectors, looking for anything that might be a problem. There were several orange wires, but all looked good.

Could it be a relay, or something in the stereo itself? I don't know much about anything electrical!

[JOHNBIGDOG]

So I hate to assume. When you say that the radio turns off, your listening to the radio you turn the headlamps on, then the radio goes blank and no reception as if you turned it off, does your instrament cluster go dim as well.

Turn the brightness up on the dimmer switch up? the headlamp switch sens out a signal to tell other moduales how bright to be ans is a seperate signal to the radio.

[fasternu]

When I turn on the lights, the radio goes completely dead (not even the buttons light up), but everything else on the dashboard functions totally normal. There isn't anything that goes dim, or surges, or anything that would indicate anything out of the ordinary. I have tried dimming or making the dash lights brighter, interior lights on or off, and any other combination I could think of and got no new clues, just the radio goes completely dead. Shut off the lights and it works fine.

I am thinking about going to a junkyard and seeing if they have one I could try to plug in place if the current stereo just to try to see if it is the stereo itself, or wiring going to the radio. I also have thought about buying a new harness, but I hate the thought of trying to replace that on my own.

[fishing tech]

stock radio or aftermarket?

[fasternu]

Original stock, OEM.

[Scott K]

I would be checking for a bad ground.

[fasternu]

I found 3 grounds connected behind the kick plates, one on the driver's side, 2 on the passenger side, and checked them. Clean and tight. any suggestions on other places to look for ground wires?

[JOHNBIGDOG]

Just because the ground connection to the frame is ok doesnt mean that the wire is ok.

Do this key on engine off.

Try this, pull fuzes F6(15A) and F40(20A), in the in cab fuze pannel, one at a time then turn on the headlamps with the radio on and tuned to a strong radio station and report the results.

[fasternu]

I had called the local dealer and was set to take it in on Friday. Thursday night on the way home from work, I noticed that everything was fine again. Called the dealer and we decided to wait and see if it comes back or not.

I am curious about your possible solution, so I will be sure to keep an eye on it, and give it a try if the problem returns again. I agree though, it does seem like a ground wire problem, I just look at all the wires under the dash and my eyes glaze over.

[JOHNBIGDOG]

one fuze powers the headlights, the other powers the dimmer, It gives us a better idea witch system is causing the problem.