OEM fog lights and how to wire them [Archive] - JKowners.com : Jeep Wrangler JK Forum

: OEM fog lights and how to wire them


dougnpj
02-18-2008, 07:37 PM
When I bought my jk it did not come with the factory fog lights. I have added a new bumper that has the holes for them and I have picked up the lights. My question is does any one have the wire diagram so I can hook them up? I noticed that they have 2 pin type connectors, is one just a ground and all I have to do is run 12 volts to them like any other light???

PhilD
02-19-2008, 07:09 AM
is one just a ground and all I have to do is run 12 volts to them like any other light???Yes, just connect them up to 12v and they will work fine.

Dustoff '68
02-19-2008, 08:08 AM
...how in fact do you wire these lights, and how is the connection made to the light stalk inside? There is an additional control that has to be added to the light stalk...

John L
02-19-2008, 08:14 AM
When I bought my jk it did not come with the factory fog lights. I have added a new bumper that has the holes for them and I have picked up the lights. My question is does any one have the wire diagram so I can hook them up? I noticed that they have 2 pin type connectors, is one just a ground and all I have to do is run 12 volts to them like any other light???

Things to keep in mind.....
Do not run the fogs straight off a switch. It cannot handle the current and will get hot, melt, or maybe catch fire.
The 12 volts to the light must come from a switch activated relay.
If you are using factory fog wiring the signal from the factory switch can trigger the relay.
The factory relay cannot handle the higher current from aftermarket fogs.
Hope this helps:D

PhilD
02-19-2008, 08:29 AM
The factory relay cannot handle the higher current from aftermarket fogs.He's installing factory fogs.

A switch, relay and some wire is all he needs. I like to run the + source for my switches from an ignition switched source, that way when the ignition is off, so are the lights.

John L
02-19-2008, 10:46 AM
He's installing factory fogs.

A switch, relay and some wire is all he needs. I like to run the + source for my switches from an ignition switched source, that way when the ignition is off, so are the lights.

Exact opposite here, I don't want to rely on having the key in to have lights. I sometimes have to leave the vehicle with the lights on to have a look at something and don't like leaving the key in it. I'll take a run down battery over a stolen vehicle anyday.....:)

dougnpj
02-19-2008, 12:10 PM
OK. Thanks for the answers. But huh? Lets pretend I donít have any idea what we are talking about. (ok so thatís not much pretending) . So a hot wire to a switch, then to a relay, from said relay to one of the pins on the lights. The other pin just ground it? Is it a special relay, watts amps volts????

Dustoff '68
02-19-2008, 12:29 PM
....do not the factory lights (round OEM foogies mounted in pairs in license plate area on OEM front bumper) on originally equipped from the factory;) JK's turn on using the light stalk by the steering wheel, and if so (which they do, like all other Jeeps with fogs), then are we failing to address the OEM install (that stalk needs to be replaced with one that has the additional rotary switch...)?

John L
02-19-2008, 01:09 PM
OK, I agree w/Dustoff, what is your current config in the Jeep?
Are you adding factory fogs or aftermarket fogs?
If factory, are you planning on changing out the turn signal stalk?
Most all aftermarket fogs come with the relay, wire harness, and switch. Most have very good instructions for the install.

Basically you want to control the lights with the relay because the contacts in the relay can handle the high current demands of the lights. The relay is controlled with a switch, which dosen't have the high current capabilities that the relay has. You end up really with two switches, the low current one controlling the high current one, which in turn controls the high current load.


FWIW,I've read that even if you change the stalk out and use factory wire harnesses, you still have to take it to the dealer for a flash to "tell" the computer it now has fogs before they will work.

venom
02-19-2008, 01:31 PM
If I understand correctly,
your jeep came without the light option and you bought a factory bumper with factory lights.
If all you want to do is make them work, you need a 12V 30amp relay, a 12V 30amp fuse& holder, a switch (unless you want to pay megabucks and swap your turn signal stalk for one with the factory fog switch built in) and some decent wire (~12-14 gauge).
Here's a simple diagram that shows how to wire a switch, relay and lights.
http://www.offroaders.com/images/projects/lightforce/wiring-diag.gif
the fuse would go next to the battery in between it and the relay.
each light needs a hot and a ground, the relay needs a connection to the battery hot and one to a switched hot and a ground in addition to connecting to the lights.
The relay essentially acts as an electrically operated switch that can hold up to a high current load. The actual switch that you touch to turn on the lights really just turns on the relay. The relay makes contact inside and connects the wire run to your battery to the wires run to the positive leg of your fogs.
Hopefully this makes sense, if you're still foggy (haha get it? foggy!) then let me know and I'll try to enlighten you (God I crack me up!)

dougnpj
02-20-2008, 08:05 AM
If I understand correctly,
your jeep came without the light option and you bought a factory bumper with factory lights.
If all you want to do is make them work, you need a 12V 30amp relay, a 12V 30amp fuse& holder, a switch (unless you want to pay megabucks and swap your turn signal stalk for one with the factory fog switch built in) and some decent wire (~12-14 gauge).
Here's a simple diagram that shows how to wire a switch, relay and lights.
http://www.offroaders.com/images/projects/lightforce/wiring-diag.gif
the fuse would go next to the battery in between it and the relay.
each light needs a hot and a ground, the relay needs a connection to the battery hot and one to a switched hot and a ground in addition to connecting to the lights.
The relay essentially acts as an electrically operated switch that can hold up to a high current load. The actual switch that you touch to turn on the lights really just turns on the relay. The relay makes contact inside and connects the wire run to your battery to the wires run to the positive leg of your fogs.
Hopefully this makes sense, if you're still foggy (haha get it? foggy!) then let me know and I'll try to enlighten you (God I crack me up!)

The jeep did not come with fog lights. I bought an after market bumper that has the holes in it for the OEM lights. I bought the OEM lights. I do not want to buy the factory switch. And I think the diagram you gave will not leave me foggy (and I did get and it did crack me up). So to recap, hot wire to switch, switch to relay, relay has a hot wire to it from the battery, from the relay to one of the pins on the light, and the other pin needs to be grounded? Does it matter which pin is hot?
Thanks for all the help I know glass not electrical.

venom
02-20-2008, 12:44 PM
yeah it matters on the relay which pins wire to what
most have a little diagram on them that shows what's what
there will be 2 connectors that are your 'pass through' where one runs to the battery, the other to the lights. these are the 2 that get connected when you supply power and ground to the other two.
there are a couple of electrical symbols you will be looking for...
___/ means a switch and the little horizontal lines shaped kind of like an arrow means ground
its pretty easy to figure out which is which with a relay, you can always take a wire and try power and ground to different terminal combinations till you hear it click, shouldn't be able to hurt anything as long as no other wires are hooked up.
When you find a pair of terminals that hot on one and ground on the other makes the relay click, then the other 2 are you battery and light positive connections - those 2 usually don't matter which is which, battery vs light.
The click connections are the ones you'll ground and then wire your switch to, so when you flip the switch, you supply hot and the relay clicks and the lights come on.
I hope that made sense :grinpimp:

PhilD
02-20-2008, 12:57 PM
This may help:

venom
02-20-2008, 04:02 PM
thanks Phil, I can never remember the terminal numbers!

PhilD
02-20-2008, 04:19 PM
thanks Phil, I can never remember the terminal numbers!I can remember the numbers, I just can't remember which one connects to what ;)

The Clam
02-21-2010, 01:08 PM
This may help:

Sorry for any duplicate bumps here.. I'm trying to answer my questions wiht search and there are lots of posts that come close to answering my question.
I'm doing the same thing as the OP, but not adding a switch. Can I tap into the parking lights or low beam (green wire on the headlight, correct?) and wire it into the switch location (86 terminal) on the relay in lieu of a switch?

Thanks!

John L
02-21-2010, 03:16 PM
Sorry for any duplicate bumps here.. I'm trying to answer my questions wiht search and there are lots of posts that come close to answering my question.
I'm doing the same thing as the OP, but not adding a switch. Can I tap into the parking lights or low beam (green wire on the headlight, correct?) and wire it into the switch location (86 terminal) on the relay in lieu of a switch?

Thanks!

You can, but run the risk of throwing a code or overloading the system you tap into. Plus, the current going to the headlights is pulse width modulated (PWM), which means that if you connect the relay to the low beam headlamp circuit to relay will buzz (pulse very fast), your fogs will be dim, and the relay contacts will eventually fail.

Just curious here, why don't you want to add an inside switch?

The Clam
02-21-2010, 03:19 PM
You can, but run the risk of throwing a code or overloading the system you tap into. Plus, the current going to the headlights is pulse width modulated (PWM), which means that if you connect the relay to the low beam headlamp circuit to relay will buzz (pulse very fast), your fogs will be dim, and the relay contacts will eventually fail.

Just curious here, why don't you want to add an inside switch?

Thanks for that info.. how about to the parking lights?

Honestly, I don't care that much if they are switched, or if they are on all of the time when we turn on the headlights, as I want the extra light that they will give. SI don't care that much, I figured why go through the extra effort and expense of adding a switch.

John L
02-21-2010, 04:38 PM
Thanks for that info.. how about to the parking lights?

Honestly, I don't care that much if they are switched, or if they are on all of the time when we turn on the headlights, as I want the extra light that they will give. SI don't care that much, I figured why go through the extra effort and expense of adding a switch.

I don't know if the parking lights are PWM'd, I would guess that they are. Almost every 12v signal in the Jeep is, with the exception of one of the power outlets in the lower dash.

The extra effort and expense is minimal, especially if you are already in there doing the install for the lights. Be aware that in some states it is illegal to run foul weather lighting when the weather is not foul. There is also the requirement that the lights must switch off when the high beams are on.

If you want to see better at night, upgrade your headlights. There are many threads on this board on headlight upgrades. I personally did the CIBIE upgrade, well worth the extra effort and cost.

The Clam
02-22-2010, 02:51 PM
I don't know if the parking lights are PWM'd, I would guess that they are. Almost every 12v signal in the Jeep is, with the exception of one of the power outlets in the lower dash.

The extra effort and expense is minimal, especially if you are already in there doing the install for the lights. Be aware that in some states it is illegal to run foul weather lighting when the weather is not foul. There is also the requirement that the lights must switch off when the high beams are on.

If you want to see better at night, upgrade your headlights. There are many threads on this board on headlight upgrades. I personally did the CIBIE upgrade, well worth the extra effort and cost.

Thanks for your thoughts John.
I guess the extra effort I'm talking about would be going through the firewall and mounting a switch. What I'm thinking would only be wireing the fogs, tapping/splicing either the parking or low beams, wireing up to relay and then battery; all under hood stuff mostly.

any other thoughts expereiences out there? I know I've read others that have done it, how has it held up?

bthibodeaux
02-22-2010, 03:03 PM
Thanks for your thoughts John.
I guess the extra effort I'm talking about would be going through the firewall and mounting a switch. What I'm thinking would only be wireing the fogs, tapping/splicing either the parking or low beams, wireing up to relay and then battery; all under hood stuff mostly.

any other thoughts expereiences out there? I know I've read others that have done it, how has it held up?

Tapping into the parking lights works perfect. I have done it. This way the fogs are on whenever the lights are on. Even high beams, which is not the case with the factory switch. Do use a relay as advised. The wire tapping into the parking lights goes to terminal 86 on a Bosch style relay. Terminal 87 goes to one of the pins on the fogs. The other pin on the fogs goes to ground. Terminal 30 goes to the battery (put a fuse in line), and terminal 85 goes to ground. Note that only one 30A or 40A relay is needed to run both fogs. I used insulated connectors on the fog pins, and glued/sealed them up with goop. Pretty straight forward job.

I also recommend this route to Dougnpj.

The Clam
02-22-2010, 03:47 PM
Tapping into the parking lights works perfect. I have done it. This way the fogs are on whenever the lights are on. Even high beams, which is not the case with the factory switch. Do use a relay as advised. The wire tapping into the parking lights goes to terminal 86 on a Bosch style relay. Terminal 87 goes to one of the pins on the fogs. The other pin on the fogs goes to ground. Terminal 30 goes to the battery (put a fuse in line), and terminal 85 goes to ground. Note that only one 30A or 40A relay is needed to run both fogs. I used insulated connectors on the fog pins, and glued/sealed them up with goop. Pretty straight forward job.

I also recommend this route to Dougnpj.

Thanks, I was looking for first hand info like this.:beer:

did you get a harness for the fog bulbs or just wire right into the pins on the bulbs?

bthibodeaux
02-22-2010, 03:52 PM
Thanks, I was looking for first hand info like this.:beer:

did you get a harness for the fog bulbs or just wire right into the pins on the bulbs?

Right into the pins as described. Use insulated connectors, and Goop the crap out of them. Not sure what will happen when I need to replace the bulbs, but I am hoping that the the set Goop and pins come out as a unit, and I can reuse them like a plug....

The Clam
02-22-2010, 04:38 PM
Yeah- I was thinking too about the pin attachements that are like a sleave and have plactic/rubber over the connection.. might work too..

bthibodeaux
02-22-2010, 06:14 PM
Yeah- I was thinking too about the pin attachements that are like a sleave and have plactic/rubber over the connection.. might work too..

Yep. That is what I meant by insulated connectors (sleeved spade connectors). However the connections will be much more durable and dependable if reinforced by the Goop. Good luck with it.