I’m having trouble and need help! My 02 Silverado was broken into and they destroyed the key switch cylinder and the security wires. I replaced the cylinder and the ignition switch electrical harness. It will start but instantly shuts off. I think it’s a security issue but having no luck figuring it out.
Any help is much appreciated!

 

The antitheft system is not disarming. I'm guessing you didn't replace with matching coded lock+key set, which means the system has to be reprogrammed by a dealer/locksmith.
Search the forum how to do a passlock reset and hope for the best.

 

I replaced the ignition wiring harness, under my steering column, with a used waring harness from a parts truck. I removed the ignition switch and replaced it during the parts replacement. The truck didn't need to be reprogramed or any thing like that buy there's a little push button switch just above the switch that caused a no start because it wasn't sitting correctly.
https://www.rockauto.com/info/903/1S5974_10.jpg

 

Hey frank, can you send me a picture where that is? Thanks!

 

Click on the rock auto link

 

Didn’t get a link

 

Ok I gotcha! Didn’t see that, thanks!