Wiring fog lamps can be difficult or easy. I chose easy in doing this. You can buy a wiring harness setup from your local auto shop, but the wiring in them seems to be a bit thinner.
This writeup does not wire into the stock headlamp wiring and does not have the problem of fogs running with the high lamps only. So this will work for aftermarket fog lamps, auxillary driving lights or rear fogs.
With that in mind, here is roughly what you will need.
- Wire of a sufficient gauge (14 or 16 is fine), preferably of multiple colors for + and -
- wire connectors (bullet type, spade type, your call). I prefer spade type.
If using spade, buy enough for:
your relay connections
- 3 terminal loops for your relay/lamp ground, battery connection, and switch
- 1 wire taps - T Style
- Bosch-type relay with 4 or 5 prongs (about 3.50 at your local auto parts store)
- Wire strippers
- Wire cutters
- switch (I used a Carling switch - identical to ARB locker switches)
- 2 inline fuse holders - I used the type that holds the same type fuses as the fuse box behind the dash
- wire loom
- heat shrink tubing
- kite string
Your basic wiring will be routed something like this:
First off place your lights where you want them to be. Then find a good location for your relay. I went ahead and secured the relay where I wanted it to go. This makes the next step easier.
Using the kite string, run the string along the path you want the wiring to go for the farthest light from the relay. If you want to use the actual wire, you can do this, but the kite string was easier for me. Once you have the length of the farthest light, cut 2 pieces of wire (one for + and one for -) and add a few inches since you'll be stripping ends. This will give you some wiggle room in case you measured wrong. In my setup, I used red for + and black for -.
Repeat the process for the other light.
Connect the + and - wires for each light. I used quick connect spade connectors because if I ever need to remove or replace a light, it is a lot easier to remove it using spade connectors. I used the version with the rubberized coating over them for protection from the elements.
Once you have each light wired for + and -, go ahead and insert the wiring into the wireloom however you like. I ran it from the farthest light past the closer light and used electrical tape to keep the wire from slipping out. Here is how mine looked:
Under the sway bar cover:
With all 4 wires in the loom, run the loom along that path you marked out with the string to where the relay is. If you did this right, you should have a few extra inches or so once you get to the relay. You may need to cut the loom a bit if it is too long.
Now, attach the female spade connectors to each of the 4 wires that you ran to the relay, but connect the 2 negative ones, along with a section of wire for the ground, to only 1 spade connector. In other words, you'll have 3 wires connected to one spade connector. If the gauge wire is too thick to fit all 3 ends into the connector to crimp, you can do a butt splice connecting them. Use a short section of the same gauge/color wire to run to the relay instead. This is the method I ended up using. Now back to the wires themselves.
To that third wire, connect one of the terminal rings to the other end (after you strip off a section of the cover). Refer to your relay's instructions (usually on the back of the package), to determine where to connect the positive leads.
At this point you have wired the relay to the lights. Here is my relay wired up with the positive cables from the lights and power to the battery (no fuse installed yet).
Now, we'll wire the relay to the battery, working from the relay to the battery.
Attach a female connector to a section of wire (I used red again) and plug that into the spade on the relay that runs to battery power. Using either a bullet, buttsplice, or spade setup, connect the inline fuse section. I attached the terminal ring to the other side of this inline fuse setup to reduce the amount of splices. I also used some heat shrink tubing around both connections to the inline fuse wire to further protect it/them. I attached the terminal ring to the positive battery lead. You may have a fuse panel you use for accessories, so if you do, attach it to that however it works for you.
The fuse is currently not installed, but that is okay. We'll install that before we test and finalize everything.
Now, we are ready to wire in the fuse. This will really depend on your switch, but I'll write it up as if I was using a Carling/ARB switch. My switch has an indicator when the dash lights are on, so I wired that first (and prior to this project).
Use the diagram at the beginning of this post for the Lead information referred to below.
For IPF wired lights, the stock harness has the following:
- black is ground - it will use lead #8 on the ARB switch
- red is power from the fuse block - it will use Lead #2
- white is for the relay/solenoid (for the lights) - it will use Lead #3.
Other factory switches and/or wiring harnesses are probably the same or similar.
That leaves leads 6 and 7. Lead #7 is the ground for the dash illumination and Lead #6 is the lead for dash power. Finding a power source for this, I had a couple of choices. I could use one of the orange wires from the HVAC or the stereo dimmer function, but I didn't want to splice into the HVAC and I didn't want to run a longer wire from the stereo harness to the switches. I had a wiring harness by my ARB's that was factory, but never used. I'm suspecting either rear wiper or defrost (neither of which my soft top TJ has - and won't have). I snipped the orange wire coming to this useless harness (to me) and spliced it into a setup that had 4 wires, one for each switch to be wired. I used 18 gauge wire and used insulated spade connectors to wire the #6 lead on all switches.
Now if you are using the stock bezel on the left of the TJ, you should not need to do this next step.
Now to get these wires into where the ashtray was, I drilled a 3/4" hole in the dash cover directly below the HVAC (with HVAC removed of course) and ran the wires through that hole. No problems. I have another hole for the CB wire because I relocated the CB from under the Tuffy to behind the dash.
Now, I'm ready to wire in the power between the switch and relay.
Put female connectors on the ground, power, and switch lines. I connected the ground first and ran it to a ground point on my dash. Now run a wire from the switch to the relay (see relay diagram for which connector is to be used), but there should only be one open one at this point. You can run this wire through one of the grommets in the firewall (one in the middle behind the center stack, one by left side of drivers footwell). If you are running to the center stack for your switch location, the center grommet makes more sense.
When you hook up the wire from the switch to the relay, that should be the last connector on the relay. Compare with the image below to make sure you have everything wired to the proper location (another reason why no fuses are inserted yet).
Translation for the non-electrical types like me:
85 - Where your black ground wires should hook up
86 - Where the wire from the switch connects
87 - (may have 1 or 2 of these) - red wire lines to the lights themselves
30 - Where the power to the battery connects
Attach the wire to the relay using another female spade connector. So now your switch has dash illumination, ground, and connected to the relay. Now, we need to connect the switch to a power source with an inline fuse in the wire. This may only be necessary if your switch has an indicator light when the circuit is active (which I recommend). At this point, you need to decide if you want it to be a switched circuit or a non-switched circuit. If you want it non-switched, you can run to the battery. I will only use these when the Jeep has power, so I ran mine to a switched circuit. Either way, you want an inline fuse (5 amp is fine) to protect it. Run this wire to the desired location and secure it using the wire taps. Clean up the install and run/secure these wires in a loom if possible with other wires to keep it clean and then secure it all with zipties.
BTW, Jeep has a switched wire and a non-switched wire available for use near the fuse box. You may need to search for it, but they should be there.
Now that all the wiring is done, insert the fuse(s) and test it. A 5 amp fuse should be sufficient for the fuse location going to the switch. 25-30 amp for the fuse going to the relay from the battery. If all is well, reassemble your interior parts you took off to do this install.