Fog Light Wattage Hazard?

[Mountaineer01]

Since I trimmed the bottom portion of my bumper for clearance I had to remove my stock fog lights, and I got some Hella fog lights that I would like to mount on top of my bumper. With the OE lights gone I have the wiring harness and dash button to control those just sitting unused and ideally I would like to just wire up the new lights to the existing infrastructure. Based on some online digging it is not recommended to wire a higher watt light to the existing wiring. I would think that I would just get less output from the bulbs but is this an actual fire hazard? Does anyone have any experience with this?

I really want to reduce the extra wires in the engine bay and want to utilize the existing switch for a clean look, but I don't want the truck to catch fire so I will do it the correct way whatever that is.

As I understand it the OE bulb is 45W and new is 55W so not a major increase.

[a1gemmel]

You'd be surprised how bad factory voltage drop is on some headlights / fog lights. If you backprobe at the light, you're more likely to find something like 10-11v than the 14 at your running battery, on account of the high current draw. You'd probably get away with a slight nominal wattage increase, but your lights will be brighter and you'll sleep more soundly if you fix it. The thing you're looking for is a "high beam relay kit", lots of companies make a version. It makes it so your switch is just powering a relay, and current for the lights comes in a much larger wire straight from the battery.

[Mountaineer01]

Yea I think I've installed a similar kit when upgrading the lights on an old Miata. But that was just plug and play with the stock harness. I was hoping to avoid redoing a bunch of wiring, but better be safe than sorry. How difficult will it be to wire it up to my existing switch in the cab though?

[a1gemmel]

It's pretty straightforward - the original wires going into one of the fog lights become the switch circuit (pins 85 and 86 on the relay), this way your existing switch will continue to work.

[xaza]

yes overloading a wires rated amp draw is a fire hazard. The wire acts like a heating element by resisting flow and gets hot and melts the insulation. Always use proper wire size or slightly bigger. Additionally if the power flows directly through switch that can have a lower rating. You will want to install a lighting kit with relay to protect switch. With relay kit you can use same switch though because it then is only activating the relay and not powering the lights.

[Mountaineer01]

Thank you guys for the input, I will order up a wire kit with relay to be safe. I'm glad I can re-use my existing switch though, that was my main concern.