Accessorie wires not large enough

[Fletch22]

Another question. My light bar and fog lights, as well as I’m sure a lot of other accessories out there, don’t have a large enough gauge wire coming out of them for the run I’m making. So do I just go with roughly the same size wire and hope for the best or how do you get around this? From what I understand if I’m running something that’s 12 amps for a total run of 50-60 feet say, i should be using a 6 gauge wire ... if I run 6 gauge but the couple of feet that came with the accessory is only 12 gauge for example, then that piece will overheat right?

I’m trying to wire the light bar and fog lights on the same switch with the battery and lights at the front, and switch at the back by me.

 

[TheLastCall]

Running a large gauge wire is to make up for the resistance of 50-60ft of wire. The accessory still only draws 12amps.

Technically the wire going all the way into the accessory should be a large gauge, however practically nobody does this and manufacturers don’t want to put large gauge wire due to cost.

It should be fine, just keep the smaller gauge short. The first time you run it keep an eye on it and check if it gets warm.


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[Scott F]

I'm curious as to how big your boat is that it will be 50-60 foot run from the light bar to your fuse panel.

 

[Bob9863]

I've found 12ga wire fine on light bars on utes, so it should be fine on a boat.

 

[Fletch22]

I'm curious as to how big your boat is that it will be 50-60 foot run from the light bar to your fuse panel.

16 feet. Battery at the front, back to the switch at the back of the boat, up to the lights at the bow. And all the online gauge calculators say to do the round trip. The wires aren’t running tip to tip, but they are being tucked away and run along seems and gunnels to make them hidden, that adds a few feet. So I’m basically estimating 16 feet from battery to panel, 16 up to lights (32) and back again (64).

 

[Fletch22]

I wanted the battery stored in the front cubby but I’m starting to think now that it might just be easier for the wiring if I have it at the back. Just sucks because it takes up my foot space when raising my engine and adds even more weight along with the fuel tank and me. And I’ll have to get a battery box and figure out a way to tuck away the fuse panel and negative busbar as well.

 

[earl60446]

Use a relay controlled by the switch at the console. Then you only need to run heavy wire a very short distance.
Tim

 

[CedarRiverScooter]

Or you could just have the switch at the front.

 

[Fletch22]

Use a relay controlled by the switch at the console. Then you only need to run heavy wire a very short distance.
Tim

Did some research, would a 4 pin 87 relay work? So i would wire the ground from the lights to the negative bus bar, ground from the relay to the negative bus bar, then the power from the fuse panel to the relay, then relay power to lights, and finally relay to switch?

 

[Fletch22]

Or you could just have the switch at the front.

Thought about it but if I am by myself that would be pretty inconvenient, especially if I need to turn off the headlights quickly do to another boat or something.

 

[earl60446]

Use a relay controlled by the switch at the console. Then you only need to run heavy wire a very short distance.
Tim

Did some research, would a 4 pin 87 relay work? So i would wire the ground from the lights to the negative bus bar, ground from the relay to the negative bus bar, then the power from the fuse panel to the relay, then relay power to lights, and finally relay to switch?

Use this diagram, hopefully the 87 relay is sufficient current size for your lights.
One side of lights go to grd.
power side of lights go to the N.O. 87 lead on relay.
Fused +12v to 30 lead on relay.
Relay 85 lead to grd.
Relay 86 lead to fused light switch.

 

[Fletch22]

Use a relay controlled by the switch at the console. Then you only need to run heavy wire a very short distance.
Tim

Did some research, would a 4 pin 87 relay work? So i would wire the ground from the lights to the negative bus bar, ground from the relay to the negative bus bar, then the power from the fuse panel to the relay, then relay power to lights, and finally relay to switch?

Use this diagram, hopefully the 87 relay is sufficient current size for your lights.
One side of lights go to grd.
power side of lights go to the N.O. 87 lead on relay.
Fused +12v to 30 lead on relay.
Relay 85 lead to grd.
Relay 86 lead to fused light switch.

Amazing, thank you!