87 f250 blowing turn and brake light fuses

[lekay]

Keeps blowing fuses for turn lamps and brake lights. Works fine for a bit then blows. Where to start? It calls for a 15 but I see someone has put in 20. Any help would be great.

[lekay]

I think my camper lights are wired in to the right front turn signal and thats what shorting it out.

[lekay]

Still blowing brake light fuses. Unhooked camper lights.Turn lamps ok now. any thoughts on the brake light fuse?

[bigreave]

i had the same thing happen on my 82 it would blow at random times , i would check you triler harness and the all your buld sockets for a ground out. if it has a bad spot it would pop every time you hit a bump

[lekay]

Originally Posted by bigreave

i had the same thing happen on my 82 it would blow at random times , i would check you triler harness and the all your buld sockets for a ground out. if it has a bad spot it would pop every time you hit a bump

Thanks I will check the harness and the bulbs.

[cdawley1]

Does the fuse blow with and without the trailer hooked up? If the fuse blows with the trailer hooked up, there is no doubt about what is causing it. If it blows without the trailer hooked up, I would try tracing the wiring from the brake lights back to the fuse panel. I know it is a lot of work and possibly nerve-wracking. It could be that the wiring from the brake light to the fuse panel got the insulation cut off between two wires causing a short and therefore blowing the fuse. A 20A fuse is just a little more resistance between the connection. I would not go any higher than the 20A fuse because you could possibly cause your wiring to burn up between the brake lights and fuse panel and possibly burn some other wires near the fuse panel if the problem is at the fuse panel. I know this is going to sound off the wall, but if you can't find the problem, you may have to run new wire between the lights and fuse panel to see if that still causes the fuse to blow. It could also be that your brake light connections may be corroded or wet. I know some Ford vehicles are bad about not being sealed tight enough to keep water out of the tail light lens. Hope this helps.

[lekay]

Thanks for your help.

[Garland]

You have a short to ground somewhere in the stop light wiring system. Use a wiring diagram to trace the wiring and check for burnt or missing insulation, exposed contacts, etc.

[Garland]

and you should never replace a fuse with a higher amperage fuse. Can replace them with lower amperage fuses but not higher, otherwise you've got a likely chance of burning the wiring in the system. Fuse wont blow when amperage exceeds the wirings maximum load capacity.