GM-GMC: Truck wont shut off, starter switch, mechanical work

Question
My 1985 GMC s-15 pickup truck wont shut off when I turn the key. It stays running when I turn the key off and I must pop the clutch and then disconnect the battery cable to shut it down. I've already replaced the ignition starter switch and that didn't help. Can you tell me what the problem is.

Answer
Did you replace the ELECTRICAL IGNITION SWITCH mounted on the steering column UNDER the dash or just the KEY ignition switch ?.

Have you installed ANY after market products onto the vehicle?.

What mechanical work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made.


thomas