Crash_AF
NAXJA Forum User
- Location
- Colorado Springs, CO
In order to add factory fog light wiring to a 97-99 that did not have the wiring present you need the following from whatever source you choose:
Factory switch and bezel
Header harness from fog light equipped XJ
Fog lights (with brackets)
Relay
The basic rundown is as follows:
Outside:
Open Hood
Disconnect C106 connector which is located between the front of the air box and the radiator support. To disconnect, slide red lock bar to the side before pushing down on the release lever.
Remove the header panel (fiberglass nose piece)
Unplug all lights
Remove header wiring harness from header and replace with fog light equipped wiring harness
Plug in all lights
Replace header panel
Reconnect C106
Bolt on new fog lights
Plug relay into #2 position in PDC
Inside:
Remove dash center facia by grabbing at lower corners and pulling towards you.
Remove three screws from switch bezel
Unplug all switches and power points - fog light plug is clipped into holder on bezel
Plug in new switches and power points
Test fog light operation
Replace three screws for switch bezel
Snap dash center facia back onto dash starting with the top and working down
Theory of operation for troubleshooting:
First some terms so we're on the same page.
C100 is the big square plug under the dash
C106 is the main harness to header harness connector
PDC is the Power Distribution Center under the hood
R1 is the fog light relay in the PDC
SW1 is the fog light switch
S106 is the splice in the header harness to send power to both fog lights
SW1 has four pins, Pin 1 is dash lights and Pin 4 is ground.
The light blue wire starts at SW1 Pin 2 and runs through C100 to C106 then splits at S106 to power the individual fog lights.
The violet wire starts at SW1 Pin 3 and runs through C100 to terminate at R1 Pin B7 in the PDC
Now to concentrate on R1. R1 has five pins, four are connected.
B6 is powered from Fuse 25 in the PDC and is 30 on R1 (Normally Open contact to 87)
B7 is 87 and goes to SW1 Pin 3 to power the fogs
B8 goes, via a brown/white wire, to C106, where the wire becomes red, to the hot terminal of the left headlamp, and then to Fuse 3 in the junction block. This wire switches from hot to ground depending on if you have high beams on or not. Hot when on high, ground when on low. It is still unknown how it accomplishes this feat, but it does.
B10 goes, via a brown/yellow wire, to connector C2 (which is listed elsewhere as for the PCM, don't ask why it goes there!), and then to Fuse 7 in the junction block. It also goes, via another brown/yellow branch, via C106, and splice S-104, to common hot terminals on the left-hand marker lamps.
While a simple (with the exception of the headlight connection) wiring layout, this set up is not the most efficient method of connecting fog lights because the switch is forced to carry the entire current load from the fog lights. This often causes failure of the switch due to overheating which melts the plastic.
I recommend adding an additional relay to the system to take the load off of the switch, but it will function as designed in this configuration.
Thanks to Matthew Currie for FSM assistance while creating this post.
Later,
Joe
Factory switch and bezel
Header harness from fog light equipped XJ
Fog lights (with brackets)
Relay
The basic rundown is as follows:
Outside:
Open Hood
Disconnect C106 connector which is located between the front of the air box and the radiator support. To disconnect, slide red lock bar to the side before pushing down on the release lever.
Remove the header panel (fiberglass nose piece)
Unplug all lights
Remove header wiring harness from header and replace with fog light equipped wiring harness
Plug in all lights
Replace header panel
Reconnect C106
Bolt on new fog lights
Plug relay into #2 position in PDC
Inside:
Remove dash center facia by grabbing at lower corners and pulling towards you.
Remove three screws from switch bezel
Unplug all switches and power points - fog light plug is clipped into holder on bezel
Plug in new switches and power points
Test fog light operation
Replace three screws for switch bezel
Snap dash center facia back onto dash starting with the top and working down
Theory of operation for troubleshooting:
First some terms so we're on the same page.
C100 is the big square plug under the dash
C106 is the main harness to header harness connector
PDC is the Power Distribution Center under the hood
R1 is the fog light relay in the PDC
SW1 is the fog light switch
S106 is the splice in the header harness to send power to both fog lights
SW1 has four pins, Pin 1 is dash lights and Pin 4 is ground.
The light blue wire starts at SW1 Pin 2 and runs through C100 to C106 then splits at S106 to power the individual fog lights.
The violet wire starts at SW1 Pin 3 and runs through C100 to terminate at R1 Pin B7 in the PDC
Now to concentrate on R1. R1 has five pins, four are connected.
B6 is powered from Fuse 25 in the PDC and is 30 on R1 (Normally Open contact to 87)
B7 is 87 and goes to SW1 Pin 3 to power the fogs
B8 goes, via a brown/white wire, to C106, where the wire becomes red, to the hot terminal of the left headlamp, and then to Fuse 3 in the junction block. This wire switches from hot to ground depending on if you have high beams on or not. Hot when on high, ground when on low. It is still unknown how it accomplishes this feat, but it does.
B10 goes, via a brown/yellow wire, to connector C2 (which is listed elsewhere as for the PCM, don't ask why it goes there!), and then to Fuse 7 in the junction block. It also goes, via another brown/yellow branch, via C106, and splice S-104, to common hot terminals on the left-hand marker lamps.
While a simple (with the exception of the headlight connection) wiring layout, this set up is not the most efficient method of connecting fog lights because the switch is forced to carry the entire current load from the fog lights. This often causes failure of the switch due to overheating which melts the plastic.
I recommend adding an additional relay to the system to take the load off of the switch, but it will function as designed in this configuration.
Thanks to Matthew Currie for FSM assistance while creating this post.
Later,
Joe
