Fog light wiring, I hope I did this right.....

inklegg · **Posted:** Mon Jun 28, 2010 6:52 pm

Hello everyone,

I purchased some factory fog lights to replace the black plastic "vents" in my 03 sport (thanks jeepfrog). Here is how I wired it, please let me know if someone sees an issue, I am no wiring expert.

Using 18 gauge wire, I ran power from the accessory wire in my radio harness (so if I forget to turn them off, turning off the Jeep will do it for me). From the radio harness, I installed a 15A inline fuse to the switch. Ran the power from the switch, through the rubber gromet in the firewall and split it to each of the lights. Each light is then grounded to the frame where the wind deflector is mounted under the front bumper.

The lights work great and seem just as bright as the driving lights. My concern is even though they work now, is there a possibility of any future problems (too small of wire, fuse, no relay, incorrect power source, etc....). Anyone out there that knows wiring, please let me know if I should be concerned about anything, or if my installation is sufficient.

Thanks in advance for the help.

inklegg · **Posted:** Wed Jun 30, 2010 2:15 pm

.......No response yet? Wow, usually you guys are all over new posts! I don't know if the lack of response means I did it ok or not.

Looking for some yay's or nay's so I can either set my mind at ease or rewire.

VoodooMann · **Posted:** Wed Jun 30, 2010 2:45 pm

I personally would have gone with 16ga. or bigger wire, just for long term durability/safety. also, what wattage are the foglights, all of mine are aftermartket So I do not know the specs on the OEM.

I am guessing they are 35w, in which case a 15amp fuse should be sufficient, however if they are 55w, you might want to up it to a 20a fuse so you don't pop fuses left and right.

*edit*

you should really run a NEW power line for them and use the accessory wire from the stereo to power a relay, it is not terribly safe to be demanding that much from the radio harness.

infernicus · **Posted:** Wed Jun 30, 2010 3:18 pm

There should most definitely be a relay..

And I wouldn't take power from the radio. That's a very thin wire. And not ready to pull that much power.

If you can't come directly from the battery, even an add-a-fuse circuit is better.
http://www.amazon.com/gp/product/B001QR ... CVCCFBGNX1

Here is a video on how to wire one. http://www.youtube.com/watch?v=Yu_e5u_58XE

inklegg · **Posted:** Wed Jun 30, 2010 5:39 pm

thanks guys....ill go get a relay and work on rewiring. anyone out there know the wattage for the factory fogs? also would i be able to get a power source from inside the vehicle instead of running to the battery?

JustinP · **Posted:** Wed Jun 30, 2010 5:50 pm

Quote:

There should most definitely be a relay..

And I wouldn't take power from the radio. That's a very thin wire. And not ready to pull that much power.

I agree that powering the lights directly from the radio wire is a bad idea. Theoretically, the worst that will happen is blowing a fuse, but I dont think its worth the chance of worst happening. If you are dead set on having the lights power off with the key, you could use the radio power wire to activate/excite a relay. The radio wire is probably only fused with a 5amp or 10 amp fuse from the factory, so your 15amp is actually kinda worthless.

To prevent tons of extra work, I would add a relay, a common one from radioshack or auto store will work great, most are rated for 20amp or 30amp max (plenty for OEM), You will need to add a few wires though to install this, you will need to disconnect your switch, take the wire you ran from the radio wire and connect it to the "+" switching terminal of the relay, I would remove the inline fuse and holder and use it in a different spot later, you will have to add a ground wire from the "-" side of the relay switch, this will allow the relay to apply power to the toggle switch. Now youll need a wire to run from the "load out side of the relay to your toggle switch, ( this is a power wire, 18AWG should be fine IMO") Now connect the wire that went from the switch to the lights back to the toggle switch, (didnt need to diconnect it :oops:

),
Now the final wire will come from the battery (or other power source that can handle the load), It will run from the battery to the "load input" terminal of the relay. Install your fuse holder on this wire. Its a good idea to install as close to the power supply as possible.

This is kinda hard to follow, so Ill post up a schematic in a little bit. This seems alot harder than it is.

As far as a pwr source other than the battery, see if the interior fuse panel has a supply wire (big gauge) you can hook to without cutting/damaging the wire, that would probably suffice.

JustinP · **Posted:** Wed Jun 30, 2010 6:31 pm

Hope I made this easy enough to understand.

inklegg · **Posted:** Wed Jun 30, 2010 7:03 pm

now im a little confused.....

justinp, your diagram shows power going into the relay from two sources? and the switch going to the lights. The video link from infernicus said the 30 pin gets power in, the 86 pin is ground, the 85 pin goes to the switch, and the 87 pin goes to the fogs. what do i do with the other side of the switch, and how does it turn off the relay?

inklegg · **Posted:** Wed Jun 30, 2010 7:07 pm

actually i think i just figured it out.....

tell me if im wrong......

the power from the radio to the switch (since the switch does not require much power), from the switch to the 85 pin

87 pin goes to the fogs

86 pin goes to ground

30 pin goes to inline fuse, to power (battery/fuse box)

JustinP · **Posted:** Wed Jun 30, 2010 7:47 pm

inklegg wrote:

actually i think i just figured it out.....

tell me if im wrong......

the power from the radio to the switch (since the switch does not require much power), from the switch to the 85 pin

87 pin goes to the fogs

86 pin goes to ground

30 pin goes to inline fuse, to power (battery/fuse box)

I think I see where it was confusing, the "pwr wire to switch", probably should have been labeled "output power to switch". sorry.

I modified my original drawing, hopefully its a little clearer.
Inklegg, dont hesitate to keep asking ?s if needed, gotta learn somehow.

The "85" & "86" terminals can sometimes be hooked up either way. I.E.:"85"-gnd, "86"-trigger, or "85"-trigger, "86"-gnd, It just depends if the relay you buy has a diode. It makes no difference if you do or dont with what youre wiring, worst case, if you hook 85 & 86 up wrong, it wont work and youll switch the wire spots on the relay and have light.

infernicus · **Posted:** Wed Jun 30, 2010 8:10 pm

Yeah the wire from the radio to relay is only telling the relay that the engine is on and should allow power to the switch, not actually giving power to the lights.

The switch is then what determines when your lights are on.

So when you have the switch in the ON position, the lights turn on when the "switched ignition" wire (in this case the radio wire) when the key is in the "ignition on" position.
When the switch is in the OFF position, well the lights stay off, lol.

I hope I didn't make it even more confusing, lol.

Good luck!

inklegg · **Posted:** Wed Jun 30, 2010 8:13 pm

great.....so far i got everything rewired with 16 gauge and the relay mounted in the fuse box, just need to find power to the relay and a good ground from the fuse box

ANY IDEAS?

inklegg · **Posted:** Wed Jun 30, 2010 8:30 pm

found a ground in the kick pannel by the hood release......just need a power supply

JustinP · **Posted:** Wed Jun 30, 2010 8:31 pm

inklegg wrote:

great.....so far i got everything rewired with 16 gauge and the relay mounted in the fuse box, just need to find power to the relay and a good ground from the fuse box

ANY IDEAS?

WOW, you work fast. I wouldnt even have got the relay yet. haha. my couch is far too comfy. :goink:

For the power wire, I would go straight to the batterys positive terminal. Dont forget the fuse of course.

You can trace the batterys positive wire to see if it goes to a terminal that would allow you to hook your wire too. Something like a ring terminal.

For the gnd. Again the battery is an option. negative side of course. But that is unnecessary, the entire chassis is grounded, so anywhere there is a hole in metal. You could drill one, I wouldnt, but you could, just find a bolt/screw that goes into the metal and put it there. If it doesnt ground well, you may have to scuff/scratch up the paint where the wire attaches. DC grounds arent usually picky tho. If you trace the negative battery cable, you may find a good spot at the end of it.

infernicus · **Posted:** Wed Jun 30, 2010 8:36 pm

When you're dedicated and want to get it done already you're usually going back and forth from computer to Jeep, I just bring my laptop outside, haha.

I know you found a good ground, but for future reference, I don't think people normally ground back to the battery.. Like said, there are plenty of places to ground.
I might actually move my ground to where you put yours..

And I'm glad to hear you picked everything up so quickly, when I first started wiring in my Jeep, I was a mess, lol.

inklegg · **Posted:** Wed Jun 30, 2010 8:47 pm

yeah, im kind of one track minded and anal (soldering everything as well)

if everyone thinks wiring directly to the battery is the best thing, ill run out and get more wire. but i would prefer to wire to something in the car near the fuses/steering column (it was a pain getting through the firewall).

before i go get some more wire, anyone know of a color wire i can solder into going into the fuse box?

JustinP · **Posted:** Wed Jun 30, 2010 8:52 pm

Quote:

before i go get some more wire, anyone know of a color wire i can solder into going into the fuse box?

I dont, ive yet to wire anything into this jeep. sorry.

Boiler · **Posted:** Wed Jun 30, 2010 8:57 pm

Personally I wouldn't wire the switch on the same wire as the lights. I'd put the manual switch in line with the relays. turn the relays on and off with the switch & the accessory circuit. That way the only things that are getting full amperage across them are the lights, the main light wires, and the relays.

You can send a wire directly to the battery through a hole in the firewall. you can add a new hole or you can use one that exists on most (automatic / no clutch) KJs. If you pull up the carpet in the front left corner, you'll find the main wiring harness and you'll see where it passed through the firewall. IIRC there is a plugged hole up and to the left of it, and if you put a drill into the plug int will spin out. Next fish a coat hanger out from the inside, tape your wire to the inside end, then go under the hood and pull it through. When you attach it to the battery, it is prudent to add a fuse within about 6 inches of the battery.

Always remember to size your fuses to protect wire. If you've got 35 watt lights x2, thats about 6 amps total. A 7.5 amp fuse would be great, and 16 ga wire will be more than enough (plenty safe).

Good luck! You can check out what I did with my rack for a few ideas if you want. Scroll down about halfway on this page: viewtopic.php?p=469579#469579

inklegg · **Posted:** Wed Jun 30, 2010 9:09 pm

boiler, im not sure what the internals are with the relay, but this is how i have it wired so far (minus power)

the power from the radio to the switch (since the switch does not require much power), from the switch to the 85 pin

87 pin goes to the fogs

86 pin goes to ground

30 pin goes to inline fuse, to power (battery/fuse box)

how do i know what is "in line with the power" and where (what pin) should the switch be attached?

JustinP · **Posted:** Wed Jun 30, 2010 9:13 pm

Quote:

Personally I wouldn't wire the switch on the same wire as the lights. I'd put the manual switch in line with the relays. turn the relays on and off with the switch & the accessory circuit. That way the only things that are getting full amperage across them are the lights, the main light wires, and the relays.

Thats actually very valid. Good looking out.

This is the better way to do it. Neither is really wrong, assuming your switch can handle the 6 amps youll be pulling, but boilers way is a better practice. Keep the "high current" out of the weakest link.

Fog light wiring, I hope I did this right.....

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