LAFireboyd

iTrader: (3)

Occasionally someone will ask how to liberate foglight wiring from headlight wiring to run their foglights independently. Well, this is NOT that. This is about using a factory foglight switch to operate additional aftermarket lighting, such as daytime running lights(DRLs), headlight halos, fog/driving lights(that aren't factory-installed), light bars, puddle lights, etc.

This should work for just about any type of interior or exterior accent lighting. No relays or complex wiring is necessary, but you might want to fuse appropriately, which would probably come with the lights or kit. And a factory switch will retain the interior aesthetics, unlike an aftermarket switch that will look out-of-place.

I did this years ago when I installed Switchback DRLs/turn signals, but I never wrote about the switch.
https://www.thirdgen.org/forums/auto...rls-stock.html

This is based upon a foglight switch for 85-89 Firebirds, as seen below. But 3rdgens with different style switches can probably be wired similarly.



I "3D painted" the rear spade terminals of an 85-89 foglight switch for the appropriate wire colors in the factory pigtail.


The black wire is the ground wire. Ground it under the dash.


The grey wire carries power to illuminate the switch with the rest of the dash lights, like factory. I connected it to the blank INST LP terminal in the fuse box.

The brown wire carries power to energize the switch, itself. I connected it to a blank IGN terminal in the fuse box, so it receives power ONLY when the ignition is on, preventing the risk of accidentally leaving the DRLs on after turning off the ignition. That also means I can leave the switch ON all the time, and the DRLs will be powered on and off, "automatically," with ignition power. And I'll still have manual control when the ignition is on.


The brown/white wire carries power to illuminate the DRLs. Its terminal is energized by the power that comes into the switch through the brown wire terminal when the switch is ON.


The purple wire carries power to illuminate the switch's ON light. It's looped from its terminal to the terminal for the brown/white wire. So both terminals are energized together when the switch is ON. Therefore the switch's ON light will be illuminated only while the DRLs are illuminated.

If you already have factory foglights, but would like additional lighting, then this might work for you, too. 85-89 Firebirds have additional locations in the dash that are the same size and fit as the one for the foglight switch, so they can host factory foglight switches in lieu of the switches for which they were so designated.

In Formulas and many base Firebirds, there's a blank plug in the space for the actual foglight switch, left of the steering wheel, which is where I installed my switch.


In 85-88 Firebirds, there's a space designated for the GAIN switch, which powers the subwoofers in cars that received the Performance Sound System option. But if the car doesn't have that option, and most Firebirds didn't receive it, then there would be a blank plug in that space.

And in 85-89 Firebirds, there's a space designated for the Window Defogger Switch, which would be filled by a blank plug if the car doesn't have that option.

A factory foglight switch will fit into all of those locations. It will look a lot better than the blank plug(even if you don't wire anything to it). And it will match the rest of the interior. So plug in a switch, connect your new auxiliary lights and LIGHT UP!

USMC3782

just saw this and i appreciate the write up. I was looking at a DRL/ driving light option for my TA and hadnt thought of the blank where the gain switch is. I have a few spare bezels and foglight switches so this should work great