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How much power can I run in stock fog light circuit?

ssteve

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Putting a stubby bumper on and plan to run some 7” 90w(don’t know amp draw) driving/fog lights on top and would like to use the factory fog light wiring. I’m wondering what kind of amp draw this circuit would support? Haven’t looked at the fuse for those lights if it’s isolated from other stuff but if so can I just replace the fuse and be good to go?
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ShadowsPapa

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Putting a stubby bumper on and plan to run some 7” 90w(don’t know amp draw) driving/fog lights on top and would like to use the factory fog light wiring. I’m wondering what kind of amp draw this circuit would support? Haven’t looked at the fuse for those lights if it’s isolated from other stuff but if so can I just replace the fuse and be good to go?
Fused are sized to protect the wiring downstream. If you put a bigger fuse in and put more load on the WIRES, the smoke will get out of the wires and they won't work any more.
Never "just put in a bigger fuse" to run a bigger load on anything.
You need to know what the wire size and length is to know what sort of load it will handle.
 
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ssteve

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Fused are sized to protect the wiring downstream. If you put a bigger fuse in and put more load on the WIRES, the smoke will get out of the wires and they won't work any more.
Never "just put in a bigger fuse" to run a bigger load on anything.
You need to know what the wire size and length is to know what sort of load it will handle.
Copy that. I appreciate the info. I’ll have to see what size the fuse is and if it will work
 

mazeppa

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Each 90W device is going run at 90 Watt/12 Volt=7.5 Amps, so two of them are going to pull 15 Amps. I usually aim to go around 75-90% amps of the fuse rating, and for full time usage I'd feel safer around the 75% range.
 

Kevin_D

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The stock headlights are only 5A (60W) each, so the stock fog light won’t be any more than that.
Personally, I’d not go more than a 50W incandescent light.
LEDs, however…

Kevin
 

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ssteve

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Each 90W device is going run at 90 Watt/12 Volt=7.5 Amps, so two of them are going to pull 15 Amps. I usually aim to go around 75-90% amps of the fuse rating, and for full time usage I'd feel safer around the 75% range.
Ok sounds good. So targeting around a 20a fuse. Probably more than what will be used for the factory fogs. Might need to run a line to one of the factory aux switches then.
 

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As a point of reference BD Squadron Pro lights are too much and constantly cut out for me. That's 80W for the pair wired directly via BD's fog pocket kit.

If you want to use the fog circuit, BD's solution (after I called) was to run a relay from battery+ triggered off the fog circuit. I'm not sure I'd run more than some lighter LED fogs off the circuit directly.
 

mazeppa

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As a point of reference BD Squadron Pro lights are too much and constantly cut out for me. That's 80W for the pair wired directly via BD's fog pocket kit.

If you want to use the fog circuit, BD's solution (after I called) was to run a relay from battery+ triggered off the fog circuit. I'm not sure I'd run more than some lighter LED fogs off the circuit directly.
^
Always the best/safest solution, just make sure to add an adequate inline fuse between the output side of the relay and the device(s).
 

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For anyone interested I just tested the current draw on my stock fog lights for my 2021 Wrangler and I got 1.7 amps at 13.7 volts. That is for one lamp. And those measurements agree with the 24W rating that those lights have.
 

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Looks like accessory switches 1 and 2 have a 40 amp fuse. 3 and 4 are 15 amp. You could always run a separate relay and fuse for the lights, controlled by the accessory switch.

If I am reading the fuse box diagram correctly, all exterior lights share a 40 amp fuse. However, as posted above, wire size to the lamps may be your limit.

Personally, I'd do the switched relay method to isolate the load from the factory wiring. Might help keep the magic smoke INSIDE your factory harness.
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