How to Troubleshoot a GM Ignition Switch

The ignition switch in your GM vehicle should give you years of trouble-free performance. However, the switch is an electronic component that can fail without warning. Usually it will fail intermittently at first before permanently failing. Replacement switches can be purchased from your GM dealership if you need to replace it. Before replacing anything, however, you should troubleshoot the problem.

Things You'll Need

  • Voltmeter
  • Open the fuse panel underneath the steering column assembly. Turn the knob on the fuse panel cover counterclockwise and pull the cover down.

  • Use the diagram on the underside of the fuse panel cover to locate the fuse, and use the fuse pullers in the fuse panel to pull the fuse.

  • Check the fuse to make sure that the metal strip inside the fuse is not damaged. If it is, replace the fuse with a new fuse of the same amperage.

  • Open the hood and set the dial on your voltmeter to "Volts." Touch the red lead to the positive terminal on the battery, and touch the black lead on the voltmeter to the frame of the vehicle. The meter should read 12.6 volts. If the battery reads less than 12 volts, the battery is dead and needs to be replaced.

  • Check the ignition from inside the vehicle. Once you have confirmed that the battery is fully charged, try to start the vehicle. If you turn the ignition key to the "II" position and you do not hear the ignition switch "click" in the "III" position, your ignition switch is dead and needs to be replaced.