I agree, check the wiring and the plug at the headlight switch. Which fuse did you replace for the headlights? Your truck does not have a headlight fuse normally.

 

It was a 25 fuse, il check it and see if the head light switch is the problem

 

So, the headlight switch does get a little warm and then the fuse pops. i put a 30 fuse in it and it turned on the dash lights, i got excited. then i also realized it turned on the radio. but still no head lights or tail lights. then the fuse popped. im thinking a short?

 

I still don't know what fuse is blowing. Don't you have a chart on the back side of the plastic panel that covers the box? The headlights are not fused. The running lights are fused, and they are on a different circuit. The instrument cluster lights have their own fuse also, but their fuse is fed from the running light fuse circuit, so if the running light fuse blows, the instrument lights go out also.

 

The instrament lights do go out, and so does the radio, i dont know if the guy before me messed with the wiring putting in a new head unit in.

 

Hey Franklin 2 you seem very knowledgeable in this area I am experiencing the same issue no instrument dash lights headlights remain on after vehicle is shut down and lights are turned off constantly blowing fuse number 6 in the engine compartment fuse box when I put headlights on truck is 2002 Ford F150 supercrew. This issue started about four days ago fuse does not blow when headlight switch is in first position only when I turn it to full headlight function or second position does fuse blow no modifications have been made to the truck the only thing I can think of is two weeks ago I pulled my boat out of the lake and the trailer hitch and trailer light plug were completely submerged in water. To be on the safe side I changed every fuse in both the engine compartment and under the steering wheel dash compartment fuse panels and it is always the same number 6 fuse in the engine compartment fuse box that blows only blows when headlight switch is turned on. I have hit the headlight switch a few times with my knees getting into the truck so I tried a new switch thinking it may be damaged and the new switch does the same thing which tells me it is not a switch issue. Would taking your advice from this post and running a new wire for the tan white line fix this issue. Fuse blows instantly as soon as headlights come on split-second I put a 20 amp fuse in place of the 15 amp and I know you should not do this but it too blew it took five seconds for it to blow???? Please help I am at a loss any suggestions.

 

I believe what you are saying, but it doesn't make any sense according to the diagrams. Fuse 6 is for the running lights, not the headlights. Putting the switch out to the 1st position should be the running lights, and should be using the #6 fuse. For an experiment, pull #6 fuse out, and then put the headlight switch to the 1st position. Do the running lamps work? They are not supposed to.

If they do, pull one fuse out at a time till the running lights go out. Then see what that fuse feeds.

 

LOL I know it's an odd situation and I have tried that as well and no they don't work when I do that after the fuse blows I have discovered that to turn the headlights off you put a new fuse in Fuse number 6 and the headlights go off in my research online this is a fairly common issue with the headlights staying on and no instrument lights. But nowhere do any of the forums say how it was fixed

 

I have EXACT same problem, I mean exact.

 

LOL glad to know someone else out there is having the same issue any thoughts on how to resolve it though LOL

 

Ok, so let me get this right. Put a new fuse in, put the headlight switch in the 1st position, and the running lights all work, and it will work like this for hours, all the running lights burn, and it does not blow the #6 fuse. Correct?

As soon as you go to the headlight position, the #6 fuse blows.

All the above is what happens?

 

that is all correct, however, the last 2 days it hasnt blown, the only thing i did was to check the trailer lights plug and wiggle it a bit, thats all, im sure the problem will return so please tell me your thoughts, thanks.

 

It almost seems like the running lights circuit is trying to run the headlights also, and is blowing the fuse. If you can get it in the mode of the headlights staying on when the truck is shut off, pull the fuses till you find the one that makes the headlights go out. If you pull #6 fuse and the headlights go out, then the #6 fuse circuit must be trying to power the headlights.

If you find that to be true, you are going to have to find where the headlight wires and the running light wires are bundled together, they must be melted somewhere. I would assume right after the headlight switch would be a good place to look, and also parts of the harness around the radiator.

 

P.S. I just had a thought. Your truck should have one fuse each for the low beams, and I believe one fuse for the highbeams in the underhood fuse box. When the truck is in the "headlight won't turn off" mode, you could pull these fuses and see what happens. If nothing happens, you know the problem is further out nearer the headlights. If the lights go out, then the problem is from the fuse box to the headlight switch.

 

When number six fuse blows headlights remain on even after I pulled the blown fuse and they don't go off until I put a new fuse in the number six slot then they automatically turn off?