melting fuses in fuse box

[HOYBOY]

hey yall im having a problem melting the fuse to my tail lights on my 1995 ford f250 i had a short on my flat bed ran new wires and put a fuse in and it works just fine but my fuse gets real hot and starts to smell like burning plastic (as it should when one starts to melt) i have no idea whats causeing it but i need to get it fixed asap thanks for any help you can give me

[marine5811]

Well correct me if I'm wrong guys, but I believe fuse size is determined to protect the wiring along the circuit of a particular implement i.e. your tail lights. What gauge wire did you run to the tail lights? It should be a gauge capable of supporting the current that the tail lights pull from your batteries. If you know what the pull of the tail lights is you can determine the appropriate wire size necessary for that circuit, then use a fuse that will pop before the maximum current along that wiring is reached.

Am I off base here guys?

[glovemeister]

Nope, you are right in line.

[HOYBOY]

i ran i think 14 guage wire idk if that sounds right got a big roll for wireing up trailer lights and trailer plugs mabe i needed a bigger fuse?

[lwillson]

How many lights are on your flatbed? If you added a bunch, the factory fusing and wiring probably wasn't rated for what you have.

Did you convert a regular box to a flatbed? If it was a factory cab and chassis, there should be another harness for lights. It will have its own fuses for wiring up the lights on the flatbed. I would have to check the wiring diagram, but I believe it uses the fuse for the trailer lights.

[marine5811]

Originally Posted by lwillson

How many lights are on your flatbed? If you added a bunch, the factory fusing and wiring probably wasn't rated for what you have.

^^^ exactly what I'm thinking.

[HOYBOY]

there are four oval lights for my brake lights/turn singals/tail lights then i have 11 two inch circle lights as marker lights here is a pic dont mind the fact that they arnt straight i didnt mesure them out right

[creekfreak]

Well there you go. You need to wire to support those 11 extra lights. You need to do a load calculation, increase wire size and likely a higher ampere fuse. In the meantime, don't start a fire!

[marine5811]

^^^ exactly what he said. Find out how much current each of those lights draw either off the stickers or housings or with a multimeter. Then total up the amperage draw of each individual light. Then find out online what size wire can support that load. Then install that size wire and a fuse to protect that wire up to its maximum rating.

Originally Posted by HOYBOY

there are four oval lights for my brake lights/turn singals/tail lights then i have 11 two inch circle lights as marker lights here is a pic dont mind the fact that they arnt straight i didnt mesure them out right

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