Need help with ignition lock cylinder

[Countcristo]

Hey i just installed a new ignition lock cylinder on my 98 chevy c1500 because the old one wouldn't turn the truck off without being really careful. I bought the truck off of someone who had been modding it and he also put in a killswitch which I thought might have been the issue. So after installing the new cylinder the car won't start. I've tried seeing if the key would program but it still wouldn't turn on. Maybe an anti theft issue or need to reset the system? Everything still looks attached and I even put the old cylinder back in and it won't start. Has been a week of nightmares

 

[AK49BWL]

It will crank but not run, and your security light is flashing or steady?

If that's the case, there's a relearn procedure that has to be done for the PassLock system, it'll take about 35 minutes, so you'll probably want to hook up a battery charger.

https://my.cardone.com/techdocs/PT 77-0011.pdf

Page 2 of that PDF has the PassLock procedure.

If it won't even crank, you've got an ignition switch problem most likely.

 

[Countcristo]

Itll crank and not run and the security light goes away. I asked the parts person and they said the key needs to be programmed, but just realized that the new cylinder has not even resolved the issue. The ignition modes will not work properly. The car won't turn off without disconnecting the battery most of the time.

Thinking it could be the switch and therfore not allowing me to turn the car off to be able to program the key?

I want to try attempting changing the ignition switch but the previous owner has a killswitch installed and unsure what steps to take to accommodate for the killswitch.

 

[Bloke]

I had intermittent issues trying to start my truck for the last few years. Every once in a while the truck would crank and crank and would not start even after 15 minutes. I thought it was the key cylinder so I bought a new one for the steering wheel and changed the doors out to keep it to one key.

Well I changed it out and it started right up and it didnt even have to reprograms the passkey. Wow thought i was lucky but it turns out it didnt help the problem. So i changed out the passlock module and this time i had to do a system relearn with the new key and that fixed my problem.

I opened up the old module and it was a little charred which was causing a short. I picked up a used one at the junkyard for 10 bucks. I know ebay has them too but its a pain the arse to get to them to switch out but its worth it.