The starter switch in the steering column is bad or the starting circuit wires are corroded. You will need to remove the steering wheel and remove the switch. Inspect the wire contacts and make sure they are corrosion free. If they are fine, and you should do this while you have it apart, replace the starter switch. You can get one at Advance Auto or Auto Zone for pretty cheap.
Friday, August 9th, 2013 AT 9:19 PM