I have Daytime running lights (DRL) on my Canadian built F350. I added the cab lights and the bed rails that light up. Recently, the fuse that controls the DRL's keeps blowing and before it blows the rail lights, park lights, cab lights and dash lights all stay lit till the fuse blows.

I have run this setup over a year and have not added anything to the lights during that time.

Now, before the fuse blows, all the park lights, cab lights, dash lights and bed rail lights stay on until the fuse blows. I changed out the 15amp for a 25 to see if that was the problem and it still blows and the lights stay on until then.

I have taken the dash apart now 4 times looking for loose or shorted connections.

I think it may be the light sensor on the dash at the center of the dashboard nearest the front windscreen. Has anyone had one go bad? Covering the sensor makes no difference because the lights stay on until the fuse blows anyway. I systematically removed the lighted rails, cab lights, etc. and it still blows the fuse and i still have the park lights on in the front and the rear...

Anyone ever have that light sensor go bad?

thanks...

 

You may want to try and disconnect the lights you added to the circuit and see if the fuse still blows. If it still blows, check the wiring for signs of chafing or overheating (Did you install aftermarket bulbs in the foglights?). If you find no problem, just add a relay to power your additional lamps...

The sensor on the dash is for the auto lamp feature, that's what turns the headlights on automaticly when it gets dark. Typically when those fail the headlights never come on or just come on with ignition. I don't know how that interacts with DRL. Does the DRL turn on the headlights or just the parking lights?

How long does it take before the fuse blows? If it's right away, I'll bet something is grounding out...