2000 Blazer auto 4WD

I replaced the heater core in my Blazer and put everything back together and now the car cranks but won't start. It started just before I took the dash apart to fix the heater core but now... It seems to be getting spark and fuel. I have taken the dash back out to see if I pinched a wire or anything but it looked fine and straight forward. Anyone have any ideas where start or what to check or look for? I am lost at this point. Thanks!

 

Maybe a bent pin or partially connected connector on the connection under the steering column? I would check there to make sure that connection is together properly and tight.

 

security system? I know that mine was cranking... and not starting and it was the passlock system...

 

So what did you end up having to do?

 

wait 15 minutes for it to reset...

 

It is easy enough to check if it is the passlock system problem. You just need to look for an illuminated (possibly flashing) security light on your dash when you try and start it. The system would likely have been tripped when you removed the dash to replace the core.

To reset the system you will need to insert the key and turn to run without cranking and leave it there for no less then 10 minutes. After (supposed to be exactly 10 minutes) turn off and then try to restart and you should be ok again. The security light should stop blinking at the 10 min mark to let you know the system is reset.

 

You should not need to do a passlock relearn after pulling the dash. Nothing changed. This does not rule out that the ignition switch could have taken a poop on you, but as I said earlier, start by disconnecting and inspecting the large connector under the steering column.

 

Thanks to everyone for their suggestions. I took it back apart and checked the pins and they all seemed fine and put it back together. Tried it and it started up and is running fine. I appreciate the quick feedback. Thanks again!