I'm sure it's been brought up but I need to know what to do for my setup. Using 16 gauge wire I have two fog lights on my bull bar and four behind my grill wired into n illuminated led switch. Getting power directly from my battery and grounding to my frame. My switch keeps melting. What do I need to do?

 

Get a better switch! Don't buy ANYTHING from Trash Shack (aka Tandy Radio Shack). Their junk isn't even worth taking home! Have you measured the current that the lamps draw? Make sure that the switch (and wiring) is rated for at least that much current. You should also have a fuse in that circuit. It should be rated for roughly 1.2 to 1.5 times the expect current.

SIX lights on one 16 gauge wire sounds like way too many! But it might be ok if they're low power lights.

 

got a new switch from napa and I'm thinking about using some 12 gauge housing wire as it can handle more of a load with a fuse in the line as well. Should I have to worry still?

 

Um, are you using a relay????

 

Are all the lights powered by ONE wire? How big (amps or watts) are the lights? (Watts divided by 12(in THIS case) equals amps.) A relay would be a good idea even with small power lights since it will permit you to use the shortest length of wire with power on it and will maximize the power to the lights*.

You need to add up the current (amps) of each light on each wire to find the total amps that the wire needs to supply. Then look up a chart showing the amperage that your gauge wire can carry for a given distance and use a bigger wire or more wires if necessary. The total amperage will also tell you what your switch (or relay) and fuse(s) needs to be rated at. Relay coils use little power (~ 1/4 amp) so if you use a relay as the switching element then the switch can be pretty low rated.

You can use multiple relays, fuse and wires, etc if necessary and frankly it probably will be necessary.

* Myself, I would use a relay (and fuse) as near the battery as practical and then run the power wire from it and to the lights as directly as possible. That will maximize the power to the lights and also use the least amount of heavy gauge wire. Then you can use a small wire from the switch and to the relay to operate it's coil. Make the fuse about 25% larger than the calculated amperage. But it's not critical so you can make it 2x or more if you need to. It's just important that there be some kind of protection in the circuit. If it were me, I'd use one or two relays for the top four lights and use a separate switch with each relay. Two relays and switches and wires would allow you to run each pair of lights individually or all four. Your choice there. I'd also use a separate relay (and fuse), switch and wire for the two driving lights.