Fog light wiring question (total electrical rookie)

[James9100]

First off I know basically ZERO about wiring/electrical.
Finally decided to attempt installing my Hella 500 fog lights, don’t want to tap into my low beams so skipping the relay, this is basically what I want to do.

55w per light, total pulling about 10amps.
Questions:
-Is the 16AWG wire the kit comes with good or do I need heavier without the relay?
*I think it’s 16AWG, almost looks like 18 but that’s only good up to 5A draw, vs 16 is good up to 13A so wouldn’t really make sense for Hella to give
18AWG with the kit.
-15A fuse good?

Should I be good to go or anything I’m missing?
Also I am confident I can remember to turn the fogs off so I don’t drain my battery.

 

[C.J. Roberts]

Use the relay. If you lights came with a wiring harness, USE IT. The people who make these lights know what they're doing. If it didn't come with a harness, this diagram will show you the best way to set it up. You don't need to tap into the low beams, just whatever power source you want to use. You can go straight from the battery, or tap into a circuit that's only powered when the ignition is on. And yes, 15 amp for the lights, 10 amp for the switch.
When I wired my lights up, I used a 16 AWG for each light, fed by a 14AWG wire up to the split. But I tend to overkill everything. The supplied wiring should be fine.

 

[James9100]

Use the relay. If you lights came with a wiring harness, USE IT. The people who make these lights know what they're doing. If it didn't come with a harness, this diagram will show you the best way to set it up. You don't need to tap into the low beams, just whatever power source you want to use. You can go straight from the battery, or tap into a circuit that's only powered when the ignition is on. And yes, 15 amp for the lights, 10 amp for the switch.
When I wired my lights up, I used a 16 AWG for each light, fed by a 14AWG wire up to the split. But I tend to overkill everything. The supplied wiring should be fine.
View attachment 471259

Well… not the answer I wanted to hear (I may have started snipping sections of the harness to use ) but maybe the answer I needed, easy enough to get it back together with some butt connectors.

Also just for my own understanding, why is it a big deal to skip out the relay? I thought all it did was not allow the fogs to come on with the high-beams.

 

[C.J. Roberts]

You could do it without the relay, but it would require running larger wire through the entire circuit. The switch isn't made to have that much power running through it, and would eventually fail. By using the relay, the switch only powers the relay, which only used MAYBE 2 amps, instead of the amperage of the entire system. It's also more efficient to have the amperage for the lights themselves make the shortest run. Every inch of wire that the power runs through adds resistance, which takes power from the lights themselves.
You and I both mentioned the AWG of the wire to the lights as being 14 or 16 AWG. The switch, however can be run with 18 AWG wire.
The factory circuitry runs through two relays actually. One powers the fog lights, while the second removes power from the first when the high beams are turned on. You don't need to do that.

 

[James9100]

You could do it without the relay, but it would require running larger wire through the entire circuit. The switch isn't made to have that much power running through it, and would eventually fail. By using the relay, the switch only powers the relay, which only used MAYBE 2 amps, instead of the amperage of the entire system. It's also more efficient to have the amperage for the lights themselves make the shortest run. Every inch of wire that the power runs through adds resistance, which takes power from the lights themselves.
You and I both mentioned the AWG of the wire to the lights as being 14 or 16 AWG. The switch, however can be run with 18 AWG wire.
The factory circuitry runs through two relays actually. One powers the fog lights, while the second removes power from the first when the high beams are turned on. You don't need to do that.

Gotcha, looks like I’ll be resplicing my harness.
Thanks!

 

[C.J. Roberts]

Gotcha, looks like I’ll be resplicing my harness.
Thanks!

Glad I could help. Let me, or the rest of us for that matter, know if you need anything else.

 

[NskLJ]

Glad I could help. Let me, or the rest of us for that matter, know if you need anything else.

186 milliamperes if I remember correctly

 

[7slotMT]

I typically wire lights with a single pole, double throw switch (SPDT (On/Off/On)) so that if you throw the switch one way, it can be activated when your low or high beams are turned on (your choice high/low there), or if you switch it the other direction, it is on at any time (with the vehicle started), or with the switch in the center, it is off. I typically wire up my fog lights to my low beams, and spots or floods to my high beams. That way, whenever I need tons of light with my high beams and other lights, it comes on when I turn on the high beams, and then I can just flick my light stock back to low beams and my zombie lights turn off, and my fog lights can automatically come back on with the low beams. If you would like a diagram I can draw one up for you. I am no wiring wizard either, but it's pretty straightforward.
The second benefit of this is that you don't need to remember to turn off your lights because on one side of the switch it is wired to your low beams, and the other side of the switch is wired to ignition 12v. When your car is off, all of your lights are off, no matter the position of the switch.

 

[CreepinDeth]

. The switch isn't made to have that much power running through it, and would eventually fail.

Thats the short and sweet version

Always use a relay when pullin larger loads

 

[LONGJP2]

Also just for my own understanding, why is it a big deal to skip out the relay? I thought all it did was not allow the fogs to come on with the high-beams.

You are correct about the factory fog light relay. It is for turning off the fogs when brights are on.
There are a few ways to override it.
However, the advice given is for adding a relay to keep the high current of the lights off the switch.