GM-GMC: ignition switch, gmc sierra, starter problems

Question
I have a 1993 gmc sierra 1500. If I turn the key to start the truck and let go of the key the motor keeps turning over until it fires.Is this ignition switch or starter problems.Were is the ignition switch located and can i change it myself.

Answer
Dennis,

If the switch does not return to the "Run" position by itself, the ignition switch is bad.

If the key returns to "Run," but the engine keeps on cranking, somnething is wrong with the starter or the wiring to it.

The ignition switch is located on top of the steering column and just before the column goes through the firewall to the engine compartment.  The steering column must be lowered, but not removed, to gain access to the switch.