How to Install an Ignition Switchby David Eiranova
The ignition switch, which is usually on the steering column and sometimes in the dash, lets you control the ignition system and activate the starter solenoid by turning a key. It also gives you control over other electrical systems like the radio. A faulty ignition switch may be responsible for any of the following problems: the engine will not crank or start, the engine will not shut off when the key is turned off, or the starter will not disengage when the key is returned to "Run." Replacing the ignition switch is a fairly straightforward procedure.
If your ignition switch is on the dashboard, skip to Step 6. Otherwise, begin by removing the housing of the steering column by removing the fasteners that hold it there--usually these are screws. Then remove the fasteners that connect the steering column to the dash, usually nuts that will require a socket wrench.
Move the steering column downward so that you have access to the portion of the column where the ignition switch is located. By hand, detach the electrical harness that is attached to the switch. The ignition switch is usually on top of the steering column about halfway down.
Test the exposed ignition switch with a test light. Touch the test light to the "Start" terminal, and turn the key. The light should only glow when the key is in the "Start" position. When the key is in the "Run" position, the light should glow when touched to the "Run" terminal. When the key is in the "Off" position, the test light should not glow at all.
If the switch fails the test, replace it. Remove the small nuts that affix the ignition switch, and remove the faulty switch.
Install the new switch in reverse order of removal.
For a dash-mounted ignition switch, you must remove the tumbler (lock). Usually this means inserting a small piece of wire into the provided hole, turning the key and pulling the tumbler out. Then disconnect the wires and replace the ignition switch in reverse of removal.