... All of my wiring and components seem to be in perfect working order (except clockspring, see below)
The clock springs needs to be fully functional and the steering wheel switches have to be the correct version for your model year. You should bypass the clock spring and the suspect wires with a test wire.
You will need to understand and follow the clock spring safety procedures.
AIRBAG and CLOCK SPRING
SYSTEM OPERATION
The clock spring is mounted on the steering column behind the steering wheel. This assembly consists of a plastic housing which contains a flat, ribbon-like, electrically conductive tape that winds and unwinds with the steering wheel rotation.
The clock spring is used to maintain a continuous electrical circuit between the instrument panel wire harness and the driver side airbag module, the horn switch, and the vehicle speed control switches on vehicles that are so equipped.
The clock spring must be properly centered when it is installed on the steering column following any service removal, or it will be damaged. See the Clock spring Centering procedure for more information.
The clock spring cannot be repaired. If the clock spring is faulty, damaged, or if the airbag has been deployed, the clock spring must be replaced.
WARNING: THE AIRBAG SYSTEM IS A SENSITIVE, COMPLEX ELECTROMECHANICAL UNIT. BEFORE ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIRBAG SYSTEM OR RELATED STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENTS YOU MUST FIRST DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE. THEN WAIT TEN MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO DO THIS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
XJ PASSIVE RESTRAINT SYSTEMS
REMOVAL AND INSTALLATION
(1) Turn the steering wheel until the front wheels are in the straight-ahead position before starting the procedure.
(2) Disconnect and isolate the battery negative cable. If the airbag has not been deployed, wait ten minutes for the system capacitor to discharge before further service.
(3) Remove the driver side airbag module as described in this group.
(4) If the vehicle is equipped with the optional vehicle speed control, unplug the speed control switch wire harness connector in the steering wheel.
(5) Remove the nut that secures the steering wheel to the steering column upper shaft.
(6) Remove the steering wheel with a steering wheel puller.
(7) Remove the steering column opening cover.
(8) If the vehicle is so equipped, move the tilt steering column to the fully raised position.
(STEPS 9,10,11 are optional and performed only if required)
(9) Insert the key in the ignition lock cylinder and turn the ignition switch to the On position.
(10) Insert a small screwdriver or pin punch through the access hole in the lower steering column shroud and depress the ignition lock cylinder retaining tumbler (Fig. 13).
(11) While holding the retaining tumbler depressed, pull the ignition lock cylinder and key out of the ignition lock housing.
(12) Remove the three screws that secure the lower steering column shroud to the upper shroud.
(13) If the vehicle is equipped with a standard non-tilt steering column, loosen the two upper steering column mounting nuts. If the vehicle is equipped with the optional tilt steering column, move the tilt steering column to the fully lowered position.
(14) Remove both the upper and lower shrouds from the steering column.
(15) Unplug the two wire harness connectors from the steering column side of the clockspring.
(16) To remove the clockspring, carefully lift the locating fingers of the clockspring assembly from the steering column as necessary. If the clockspring locating fingers are broken, be certain to remove the broken pieces from the upper steering column housing. The clockspring cannot be repaired. It must be replaced if faulty or damaged, or if the airbag has been deployed.
(17) When installing the clockspring, snap the clockspring onto the steering column. If the clockspring is not properly positioned, see Clockspring Centering in this group before installing the steering wheel.
(18) Plug the two clockspring wire harness connectors into the steering column side of the clockspring. Be certain that the wire harness connector latches are fully engaged.
(19) Reinstall the steering column shrouds and ignition lock cylinder.
(20) Reinstall the steering column opening cover as described in Group 8E - Instrument Panel Systems.
(21) The front wheels should still be in the straight-ahead position. Install the steering wheel being certain to fit the flats on the hub of the steering wheel onto the formations on the inside of the clockspring. Pull the wire harness through the lower hole in the steering wheel hub. Tighten the steering wheel nut to 61 N·m (45 ft. lbs.). Be certain not to pinch the wiring between the steering wheel and the nut.
Install the airbag module as described in this group.
ADJUSTMENTS
CLOCKSPRING CENTERING
If the rotating tape within the clockspring is not positioned properly in relation to the steering wheel and the front wheels, the clockspring may fail during use. The clockspring must be centered if it is not known to be properly positioned, or if the front wheels were moved from the straight-ahead position with the clockspring removed during any service procedure.
WARNING: THE AIRBAG SYSTEM IS A SENSITIVE, COMPLEX ELECTROMECHANICAL UNIT. BEFORE ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIRBAG SYSTEM OR RELATED STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENTS YOU MUST FIRST DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE. THEN WAIT TEN MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO DO THIS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Turn the steering wheel until the front wheels are in the straight-ahead position before starting the centering procedure.
(2) Disconnect and isolate the battery negative cable. If the airbag has not been deployed, wait ten minutes for the system capacitor to discharge before further service.
(3) Remove the airbag module as described in this group.
(4) If the vehicle is equipped with the optional vehicle speed control, unplug the speed control switch wire harness connector in the steering wheel.
(5) Remove the nut that secures the steering wheel to the steering column upper shaft.
(6) Remove the steering wheel with a steering wheel puller (Special Tool C-3428B).
(7) Rotate the clockspring rotor clockwise to the end of its travel (Fig. 14). Do not apply excessive torque.
(8) From the end of the clockwise travel, rotate the rotor about two and one-half turns counterclockwise, until the rotor flats are horizontal. If the clockspring wire harness is not at the bottom, rotate another one-half turn.
(9) The front wheels should still be in the straightahead position. Install the steering wheel being certain to fit the flats on the hub of the steering wheel onto the formations on the inside of the clockspring. Pull the wire harness from the clockspring through the lower hole in the steering wheel hub. Tighten the steering wheel nut to 61 N·m (45 ft. lbs.). Be certain not to pinch any of the wiring between the steering wheel and the nut.
(10) Install the airbag module as described in this group.