So I decided to document what I did to put factory fogs in an '00 XJ that did not come with them.
So at a local boneyard I found some of the pieces I need. Found a newer body style XJ that had factory fogs. Took the whole bezel with the factory fog light switch and clipped the wires for everything in there, lighter, rear defogger, etc, as far back as I could. Now you will need the factory bezel with the fog light switch because you can not clip the fog light switch itself into a bezel out of a XJ that did not come with them. Also you will want to hope that the cigarette lighter and power plug work. I figured I would just swap over my switches, lighter, and power plug to the new bezel. I know they all work. Well for the life of me I could not figure how to get the cigarette lighter and power plug out. Stalked the internet and could not find out how. All the while thinking I can not be the first person to have asked this question. Even asked the parts guy at Jeep and he thought they might use a special tool to do this. Now you would think that you could just punch out the blank on your non-factory fog light bezel and clip in the switch, no need for the bezel out of the factory fog light Jeep, but it does not work that way. The sides it would clip into are not there. Just look at your rear wiper switch to see what I am talking about. When you remove your non fog light switch bezel you will find a plug back there. Least I did. So what happens is that if your Jeep did not come with factory fogs there are no relays in the PCM, the fuse box in the engine compartment, and also if you look where the relays go there are not any clips in there to plug in a relay. At least in mine it is that way. You will also need the fog light connectors off the front harness. These connectors will also be the same on a Grand Cherokee, '93-'98 (I am guessing) and you are more likely to find them hanging up front even if the Grand Cherokee did not come with factory fogs. Not likely on a non fog light XJ.
Also I bought these:
Used 4 M8x1.25x16 Hex Cap Screws 8.8 and 4 lock washers in the appropriate size to bolt them up.
Now what I have discovered. The plug in the back of a non factory fog light switch Jeep has 4 wires in it.
Black is ground
Purple is for the 12V run source for the switch
Blue will be the 12 volt out to the relay
Orange is the illumination for the switch.
Not the on light but the symbol when you turn on the headlights.
Now here is the cool thing. It appears the black and orange are hooked up. At least in my Jeep. When I plug in the Factory switch and turn on the headlights the symbol lights up. So this is why I am assuming the black is hooked up. There is no power to the blue or purple wires.
Now I wanted my fog lights to run even if the key is not even in the ignition. Here is a list of what I bought. Some things because of the packaging you end up with extra of.
I recommend buying these at Napa because I know they work or because you get the amount you need with out too much extra.
Fuse Tap NW 785135
Relay LIT 192D
Wire Terminal / Connector Assortment NW 785158
In-Line Fuse Holder NW 784623
Black Primary Wire 16 guage 35' Roll (Was enough for everywhere I used 16 gauge wire) BEL 785400
This stuff I also bought at Napa but you will end up with more then you need. You might want to find it elsewhere. So at to not end up with to much extra or just to save a couple bucks. Harbor Freight might be a good bet.
Primary Wire Ring Terminal (Used 2 will get about 6) NW 784346
Black RTV (Just used a little dab. Will explain later) BK 7651589
3M Electrical Tape (You can buy cheaper tape but the 3M stuff works best) MMM 06132
1/4" Split Loom (Used about 30'. This you might want to buy at Harbor Frieght. Be a little cheaper maybe.) NW 737299
Rubber Grommet (Will need one but get about six) NW 784632
I bought 2' of 12 gauge black wire (part # 5545R) and 2' of 12 gauge red wire (part # 5545K) at Napa. This is something my Napa sells but gets from a different source then Napa. No link on their website because of that. It is just that you need so little that you do not want to buy a roll of it. I am sure you can find a place that sells 12 gauge wire by the foot.
Obviously you will also need a wire crimper and I used dykes to cut the wire.
Stuff I bought at Harbor Freight.
18-22 Gauge Watertight Heat-Shrink Butt Connectors Item#66595
10-12 Gauge Watertight Heat-Shrink Butt Connectors Item#66597
Marine Heat Shrink Tubing Assortment Item#67598
8 in. Black Cable Ties Item#34635
1/4 Split Loom (Bought mine from Napa but it might be cheaper here, loom is loom, and 2 14' packages might do the job) Item#66985
So using the last diagram you will leave the black and orange wires alone. I used 16 gauge wire to wire almost everything. Used 12 gauge wire for the rest. I used heat shrink butt connectors everywhere and used heat shrink tubing on top of most of them. Maybe that is overkill but I already own the cheap Harbor Freight heat gun so I figured why not.
So put your key in the ignition and turn it on without starting. Get the shifter out of your way. Now grab the bottom of the big bezel that has the vents in the top and goes all the way down to the console. Going to have to give it a good yank, it just clips in, but you still do not want to break anything so be carefull. Now unscrew the plate with the cigarette lighter, etc in it. Disconnect all the plugs and put it aside. Remove your glove box. It is just 3 screws in the hinge. Remove your fuse box door. Remove the screws from the plastic interior piece running at the bottom of the passenger side door. This it too get the kick plate around the fuse box off. Will need a socket for the speed nut that is holding it in. This is just to get room to run wire and loom up and around from the switch to the fuse box. So cut the purple wire and attach some 16 gauge wire with a red butt connector at the switch end. I recommend using a shoelace to see where you will run the wire first. Also give you an idea of the length you need and found, in most cases, it is easier to loom before finalizing any wire connections. You will attach the other end of the wire to the fuse tap. Now like I said I wanted my fogs to run without the key even being in the ignition. Smart idea? Anybodies guess. Fuse slot 13 is open in the fuse box. Has power all the time. So I used that. Now because the relays get in the way, on the left of slot 13, you will have to put the fuse tap in upside down. Use the supplied 10 amp fuse and make sure you put it in the slot that is farthest away from the prongs that go in the fuse box otherwise there is no power. Because Jeeps have a habit of leaking, especially on the passenger side I used a little of the heat shrink tubing around the butt connector on the fuse tap just in case. Do not forget to put the heat shrink tubing on before you crimp any connectors. Now plug the connector into the fog light switch. If everything went well when you turn on the fog light switch the green indicator light should go on. Put all that stuff back together that you dismantled on the passenger side. Done.
Now we need to wire to the relay. I placed my relay on the inner fender, with a sheet metal screw, near the battery. For ease of access to the prongs instead of having the relay point down I put the prongs pointing towards the front of the Jeep. For the inline fuse there is a metal bracket that the PCM (fuse box in the engine compartment) and the coolant overflow tank uses. Happens to have a couple holes in it. Attached it there with a smaller nut, bolt, 2 washers (one for each side), and maybe used a lock washer that fit. Now I wanted to come up through the passenger side but with all the stuff there, heater core, blower motor, evap core, etc, was afraid to drill. So I came up under the dash and through the firewall on the driver's side. If you look in the engine compartment you will see a bunch of wires coming through the fire wall below the Power Brake Booster. Above it is a disc of some sorts. Can also see all this from up under the dash. Decided to come through there. Using a 1/2" drill bit, plenty of room to get a drill in there from inside the engine compartment, I made a hole. Rat tail filed it a little more to get one of those grommets from above to fit in there. Those grommets are big enough to push the loom through. This is where I used a dab of RTV inside and out just to seal it up a bit. Cut the blue wire and used 16 gauge wire and a red butt connector again. Run it up under the dash, through the grommet, along the firewall, inner fender to the relay. Attached it to loomed wiring already there with a couple of cable ties. You will attach this wire using one of the blue spade connectors in the assortment pack to terminal 85 on the relay. Heat shrink tubed that too. Now when you throw the fog light switch you should be able to hear/feel the relay click. Now you can plug in all the switches, screw back in the face plate, and reclip in that big bezel. Done
I used black 12 gauge wire for the ground from the relay, terminal 86 with one of the yellow spade connectors, to the battery using one of the yellow eyelets. The eyelets fit around the bolts in the battery terminal. Just so you know I never did disconnect my battery. Might have been a smart thing to do but all went well. Later I will tell you why you might want to though. Loomed this and used heat shrink tubing at both ends. Done.
Attached some of the red 12 gauge wire to both ends of the inline fuse to lengthen the wire using the yellow butt connectors (also heat shrink tubed and loomed them). Used a yellow spade connector at one end (also heat shrink tubed and loomed) to terminal 30 on the relay. Used one of the yellow eyelets at the other end (again with the heat shrink tubing and loom) and attached to the positive terminal battery bolt. Used a 20 amp fuse in the inline fuse holder. Done
As I told you I bought the OEM type fog lights that come with connectors and bolt right up. Stole the front harness fog light connectors off a donor Jeep. I used the 16 gauge wire here to because it was close in size to the wire on the front harness fog light connectors. Now my wires are black and blue here. Blue is power. Black being ground. So I wired one fog light blue wire to terminal 87 using a blue spade connector at the relay end and a red butt connector at the other end to attach to the connector I stole off the donor Jeep. Did the same with the other fog light using terminal 87a. Again looming and heat shrink tubing everything. Now I was planning to ground each fog light somewhere below but had more then enough wire so I decided to ground both fog lights to the negative battery terminal. I used one of the yellow eyelets and was able to crimp both ground wires in there and attached to the negative battery terminal bolt. Again using a red butt connectors on each ground wire off the fog light connectors stolen from the donor Jeep. Again all loomed and heat shrink tubed at both ends. Now why you might want to take out your battery. I ran the loomed power and ground wires to the fog lights in front of the battery through where the headlight loom goes. In hindsight it would have been easier without the battery in the way. Thing is I needed the battery in place to determine proper wire length for the ground wires. If you ground to the uni-body somewhere then you will not care. Done.
Right or wrong this is what I did. Hope this helps. This resulting from research on the internet and the advice of a couple friends who know more then me. I am a shade tree mechanic at best. What I do know is that they work and the Jeep did not burst into flames when I turned them on. At least not yet.
Below are some shots to illustrate the description above. In the first shot you can't tell but all the switches are illuminated with the headlights on.