Newbie needs help with fog light wiring on vehicle

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
Hello everyone! New member here that wants to see if the community can help me out with something.

I am wiring about some new lights I am trying to wire into my new bronco. Just for info, the vehicle has built in switches that can be wired in the engine bay to power accessories from the main electrical system of the vehicle. The switch is in the cabin, and there is just a power lead in the engine compartment from each switch and they are all fused in the main vehicle fuse panel.

I have purchased some off road lights that are throwing me for a loop. They did come with their own wiring harness that included a relay, but I had spoken to KC and they weren't accurate with how they confirmed I could wire them to my switch panel.

Here is my issue. The lights have two sets/kinds of lights in them. Right now, I have the white wires from the pods wired to one switch and the red to another. If I flip switch 1, one of the two kinds of lights in the pods turn on. If I flip that switch off and flip on the second switch, BOTH kinds of lights illuminate in the pods. So the issue is that the one set of lights in the pod are activated by either the white OR the red wire. Of course, if I flip the switches separately, it's fine. Is there any way I can protect the setup in case BOTH switches are turned on at the same time?

Any help would be greatly appreciated, and I have attached a copy of the wiring diagram directly from KC to at least show how they say their harness should be wired. Thank you so much for any help!Screenshot_20230114-130251.png
 

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
Just for more information, the lamps can handle up to 36v, if that matters. A case where both of the switches would be on would be a mistake, so they would be switched back to where they need to be once we realized they were both on. It's more of a concern for safety in general if they ever both get switched on for a bit of time.
 

sghioto

Joined Dec 31, 2017
5,420
Just to be clear is this how you have it wired?
1673736906875.png

From your description it appears there is a diode in the Lamp assembly.
Red wire switches L1 on and Blue wire switches L1 and L2 through the diode D.

1673738198209.png
 
Last edited:

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
Just to be clear is this how you have it wired?
View attachment 285247

From your description it appears there is a diode in the Lamp assembly.
Red wire switches L1 on and Blue wire switches L1 and L2 through the diode D.

View attachment 285250
Yes, I drew up a horrible diagram that looks much worse than that, but it appears like yours is correct. I'll at least put my horrible drawing here at the end as well.

So, my concern is what will happen if I apply 12v through both the red and blue wire at the same time on your diagram with both switches on. It would not be intended, but could happen.PXL_20230114_233256145.jpg
 

sghioto

Joined Dec 31, 2017
5,420
Nothing that will damage anything.
Red switch ON = L1 ON.
Blue switch ON = L1 and L2 ON
Red switch OFF = L1 and L2 still ON
Blue switch OFF = L1 and L2 OFF.
 

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
Nothing that will damage anything.
Red switch ON = L1 ON.
Blue switch ON = L1 and L2 ON
Red switch OFF = L1 and L2 still ON
Blue switch OFF = L1 and L2 OFF.
I really appreciate your help. So I just need the make sure I understand the following is correct/okay.

Red switch ON and Blue switch OFF = L1 ON.
Red switch OFF and Blue switch ON = L1 and L2 ON
Red switch ON and Blue switch ON= smoke? 24v to L1? Okay?
 

sghioto

Joined Dec 31, 2017
5,420
If both switches are ON there is no damage if the voltage supply is the same for both switches.
If you have different supply voltages for the switches then a relay will be required.
 

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
If both switches are ON there is no damage if the voltage supply is the same for both switches.
If you have different supply voltages for the switches then a relay will be required.
Gotcha. So I would only have issues or make it 24v if I was running two separate 12v power supplies (one through each switch)? It's also okay both the switches share a ground, right?

Sorry, still learning about electrical.
 

sghioto

Joined Dec 31, 2017
5,420
There isn't any need to for two separate 12 volt supplies unless the lamps draw more current then a single supply can deliver.
The lamps share a common "ground" meaning the negative side of the power supply.
The switches would or could share a common connection to the positive side of the power supply.
Two different 12 volt supplies do not equal 24 volts when wired separately to each switch.
How exactly do you want to connect the lamps and at what voltage?
 

Thread Starter

5280Bronco

Joined Jan 14, 2023
6
Thanks for your help. So even if I have both switches on, both lamp 1 and lamp 2 will still just be getting 12v because I'm using the same 12v source through each switch?

I'm trying to end this thread, trust me. I appreciate your patience.
 
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