Help! Splicing into factory fog harness.

[JWagon]

I Deleted my factory fog lights when I installed a DV8 bumper. Added a 18” Diode Dynamics light bar. And wanted to use the factory wiring and switch. So I soldered one positive wire and one ground from the fog light chassis harness to the supplied connectors. Try and turn it on and it just flashes on for a sec and then nothing.

One question I have is , what should be done with the other positive wire? There are two positives supplying power to each individual factory fog lights. Just needed one for the single light bar. I just dead ended the unused positive one, and I suspect that may be a reason for my troubles.

Any help would be greatly appreciated!

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[Renegade]

It has individual power wires for the two factory lights so the canbus can tell you if an individual one burns out. It’s possible that you could splice the two together, but hopefully someone more knowledgeable will chime in.

 

[rob_o]

Did your truck come with halogen or LEDs factory?

 

[JWagon]

Halogen, I didn’t think that was a issue because I bought and ran some cheapo LED fogs for awhile, and they worked fine.

 

[am1978]

Why didn’t you just post-tap them instead of splicing in? You could have just tapped the one you needed.

 

[stil2low]

The supply may not be enough for the light bar, I remember trying to do this on one of my JK’s and would get a flicker out of the light bar
My JL I just ended up using the fogs power lead to trigger a relay and run a proper gauge wire from the battery to the light bar

 

[am1978]

No aux switches?

 

[JWagon]

The supply may not be enough for the light bar, I remember trying to do this on one of my JK’s and would get a flicker out of the light bar
My JL I just ended up using the fogs power lead to trigger a relay and run a proper gauge wire from the battery to the light bar

Thanks that may be the problem, the 18” light bar draws 5.7 amps. Thought one of those fog light wires could handle that. Could I add the second wire to boost the amps it’s sending? Can you connect two hots like that? Electrical has never been a strength of mine.

 

[Mr._Bill]

Thanks that may be the problem, the 18” light bar draws 5.7 amps. Thought one of those fog light wires could handle that. Could I add the second wire to boost the amps it’s sending? Can you connect two hots like that? Electrical has never been a strength of mine.

It's not what the fog light wire will handle, but the draw the computer is expecting to see from the lights. It should be within certain ranges, depending on whether the lights are Standard or LED. If the draw is more than it should be, the computer sees it as a problem.

The better way is to wire it up using a relay. Run a wire from the battery to the relay, and then from the relay to the light bar. Use the fog light wire to activate the relay. The draw on the fog light circuit from the relay will be minimal. Any light bar can then be used, within the limits of the battery wire and relay capacity.

 

[Forum Crawler]

Use a relay. Give the light its own 12 ga wires - ground and hot. Use the factory hot to trigger the relay on.

Done son.

 

[joshueTM]

Following this thread as it may be useful. I just recently bought a Diode Dynamics SS2 pod lights to replace my fog since I have a stubby bumper that deletes the stock fogs. I'm thinking of using the stock fog light harness to connect the pig tail that came with the pods. I hope you figure it out!

 

[JWagon]

I Ran a wire from the battery to a relay, and then from the relay to the light bar. Used the fog light wire to activate the relay. Diode Dynamics has harness’s to do just that . Works great now.

 

[LoneWolf1904]

I Ran a wire from the battery to a relay, and then from the relay to the light bar. Used the fog light wire to activate the relay. Diode Dynamics has harness’s to do just that . Works great now.

Sorry to bring up an old thread but which diode dynamics harness did you purchase for this? I have a 12 inch amber diode dynamics lightbar that I want to hook up to the factory fog but not entirely sure how to do it.

 

[JWagon]

Part # DD4031

Instead of using the supplied switch i used the wires going to the factory fog lights to switch the relay.

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