Replacing the ignition switch on a 1998 Jeep Wrangler entails removing the ignition switch tumbler, as well. A point many times confused is the separation of the two related parts. The key, also called the tumbler, has no electrical function; its function is strictly related to vehicle security. The ignition switch, however, is a black box located behind the tumbler, which opens and closes the electrical circuit.
Open the hood and disconnect the negative terminal from the battery, using a wrench. Move the terminal far enough away so that it can't accidentally make contact with the battery terminal. Allow 15 minutes for the circuits to rid themselves of any residual voltage before continuing.
Tilt the steering column all the way up and remove the three Number 20 Torx screws located at the bottom of the steering column cover -- two of them hold the cover together and the third holds the cover to the column. Tilt the column all the way down and separate the two bottom and top covers. The top cover must be taken off carefully from the steering wheel, side first, and lifted up over the emergency flashers. The flasher button gets broken very easily, so be careful not to place too much pressure on it as the cover is removed.
Place the ignition key in the tumbler and turn it to the "On" position. With the small Phillips screwdriver or the scribe, stick it into the hole in the ignition switch, located directly behind the tumbler. If the top of the tumbler is positioned at 12 o'clock, the hole will be at the 10 o'clock position -- it is easy to see if you look through the spokes in the steering wheel at the side of the switch. The switch is black, and the opening is silver-colored. Push the button in with either tool and pull the key tumbler straight out.
Remove the three security screws from the ignition switch -- also Number 20 security Torx bits. Notice how the security screws have a nub in the center. The security Torx bits are unique, as they have a hole in the center to accommodate this nub and allow the bit to slide into the screw.
Pull the ignition switch away from the column, enough to detach the electrical harness connectors. Plug the harness connector into the new switch. Install the new switch, making sure that the locking post for the steering wheel engages the back of the new switch. Insert the security screws and tighten.
Turn the key tumbler to the "On" position. Look inside the ignition switch at the blade in the center. This blade must engage the rear of the ignition tumbler. You may need to turn the key one way or the other to make the rear of the tumbler line up with the blade. When it appears to align, push the switch in all the way. Turn the switch through all positions to lock it in place.
Re-install the upper and lower steering column covers with the three number 20 Torx bits. Re-connect the negative terminal on the battery and tighten it with a wrench.
