SpdFrk1990

iTrader: (6)

Im looking at getting some new hella fog lights but not sure how I want to wire them up. They come with a harness and everything and the wires are a lot thicker then the factory wires. These new fogs use a h3 bulb also and up the wattage to 55watts where the stockers are like 37.5 . Would it be best to use the new harness and tie into the factory switch somehow? Could I pull the factory wires out of the wiring harness and replace them with the wires from the new harness? Just trying to find the best and cleanest way. Anyone have a wiring schematic showing how the factory wires run for the fogs?

Thanks
John

VIP1

You could wire them up the way I did mine:
http://www.fadingarrow.com/foglights.htm



Its basically plug-and-play.

I was concerned a bit at first going to 55watt, but its been a year and seems fine.

SpdFrk1990

iTrader: (6)

You think the stock wiring is sufficient enough for the extra watts though?

pentavolvo

id use the new harness and just integrate into stock switch

IMO factory wiring is inadequate

SpdFrk1990

iTrader: (6)

Whats the best way to do that. I agree the stock wiring is pretty shitty lookin.

thecobrahunter

iTrader: (1)

The wattage was a concern for me, too. But my solution was to replace the bulbs my Hella micro DE's came with, with an HID setup. Lights are really bright, and they only use 35watts power, unlike the 55watts, as you pointed out. Came out pretty good...And, (1) there's no issue with the crappy stock wiring, and (2) I was able to retain the use of the stock fog light rocker switch.

SpdFrk1990

iTrader: (6)

Nice how do the hids wire up?

WhiteBird00

iTrader: (4)

The easiest way to use the factory wiring would be to connect the relay from the kit to the factory fog light relay wiring. If you want them to work exactly like stock (they go off with the highbeams - best way to avoid legal problems) then use the purple wire at the factory relay to trigger your own relay connected to a better power source. If you prefer to be able to leave them on with the highbeams then use the yellow wire as your relay trigger.

A good source for battery power is the accessory stud on the left side fenderwell right in front of the two junction boxes. You don't have to worry about using battery power (make sure you put a fuse inline) because the factory foglight switch is only active if the parking lights or headlights are on.

SpdFrk1990

iTrader: (6)

Yup thats what I was going to use for power im not exactly sure how to replace the stock relay with the new one tho ill have to look into that. Where is the fog relay doesnt it run other things too though? The kit comes with a blue wire that you suppose to hook into a wire from the headlights also.

thecobrahunter

iTrader: (1)

What I liked about my set up is that it's a direct swap for the foglights - bulbs and assemblies. No having to worry about swapping relay assemblies.

WhiteBird00

iTrader: (4)

You don't have to replace the factory relay. In fact, if you plan to use the purple wire, you will need to leave the factory relay because that wire is the normal output to the lamps. Just add your own relay (the one in the kit) and tap into the appropriate wire at the factory relay for input to trip your relay on and off.

On the kit relay and wiring, connect relay pin 30 to fused battery power (the accessory stud is convenient), pin 87 to your new lights, pin 86 to the trigger source at the factory relay (either the purple wire or the yellow wire), and pin 85 to ground. This will give you all the current flow you need without risking accidentally leaving the foglights on because the relay won't energize unless the parking lights or headlights are on.

SpdFrk1990

iTrader: (6)

Ok I think I got what your saying. Just use the hella harness and mount the relay somewhere that comes with it. Then the blue wire that it says to tap into the headlights with connect that to the purple wire from the factory relay? Is the fog relay right there close also near that accessory stud? Which 1 is it?

WhiteBird00

iTrader: (4)

Yes, use the factory relay output to control the relay that came with your Hella harness. I'm not sure which color wires are being used in the Hella harness so I'll describe them by function...

A relay is basically an electronic switch that allows you to control (turn on and off) a high current circuit like your fog lights using a low current circuit signal. On a standard relay, pins 85 and 86 are the control circuit (known as the coil). When current flows throught that circuit the relay closes and allows current to flow through the high current contacts - pins 30 and 87. When the low current circuit through 85 and 86 is turned off, the relay opens and the high current flow through 30/87 is shut off.

In this case, you want to use the factory wiring to activate the low current (coil) circuit. Connect one end (pin 85) to ground and the other end (pin 86) to a power source that goes off and on with the foglight switch. This would be either the purple wire or the yellow wire at the factory foglight relay. Then connect one end of the high current circuit (pin 30) to a power supply like the accessory stud and the other side (pin 87) to your foglights.

You can use the Hella harness by looking at their relay to determine which pins I've mentioned are connected to which color wires. I suspect they want the blue wire connected to the headlights as the power source but that isn't necessary (I've never seen their setup so I'm not sure that's what they're doing - just check the pins and colors).

The factory foglight relay is in junction box #1 under the hood on the left fenderwell (very close to the accessory stud). The cover is labeled so you can tell which relay is which.

I hope you don't think this explanation was too basic - I just wanted to make sure we were talking about the same things.

SpdFrk1990

iTrader: (6)

Yeh I was trying to edit what I said last but im going to try and find a pdf or scan in the directions from the hella kit. It comes with a switch and everything and of course I dont want to use that. Ill see if I can get a picture of the layout then it will be much easier.