Ok, so as of last week friday I've had a unique issue. For starters I have a 96 Blazer, 4.3L. Only modifications I've done is Amp/Radio and Remote Start-Alarm.

When I start my truck it starts; zero issues. However when I try to turn it off, remove the key; it continues to run. I had to pull the battery; and once the car continued to run (both neg and pos removed.)

What I've done: Replaced the Ingition switch and removed the remote start. Still have the issue.

Ideas?

 

Definitely a short in a wire somewhere. I'd start by testing wires leading from the ignition switch under the dash, see if you can find something there. Also could be some wires near the ignition coil as well. You may be able to find the short fairly easily by (wearing gloves) turning the truck off (with the key) then jiggling wires until it shuts off. Once it shuts off, you have an idea of where to look.

I'd have an extinguisher handy too, just in case if you do that method. Never know if a wire could arc and cause problems with some leaked oil or something.

 

I would suspect the remote start job. Some how the computer is getting power from an alternate source. I would NOT disconnect the battery to kill the truck. It wont work! (As you found out) It also spikes the alternator and could very possible fry the computer. Much easier ways to kill a motor.

Grab a wiring diagram and start studying it. Find out where other power can come from. Are there any other accessories still on when it does this?

 

Remote start has been completely removed; there is no longer and wiring from it in the truck. Problem still remains. That was the first thing I disconnected.