service engine light off or dim and wont start

[soundtech]

New to this site...Thanks for new direction. Have a 2004LS with 4.2L I6 . Problem started a few days ago ,that engine cranks good but no start if the service engine light is not on or is dim, has flickered a couple of times. Can cycle the key till light stays on bright and get instant start. Have not had a chance to look for reason with cold and wet weather. Any direction would help ,I've only had TB for about 9 months with no problems

 

[Sparky]

Typically, when you have odd things that can be remedied by flipping the key back and forth that usually points to the ignition switch going weird on you. Common problem, relatively cheap, and from what I hear it isn't too hard to replace. I haven't had to replace mine so I can't speak from experience, just from what I've read. I know there is something specific about the replacement, something like counting the number of teeth or something like that, but I don't know exactly what. Someone should be able to give you the exact directions.

It is worth noting here that the ignition switch is a separate piece from the ignition cylinder - replacing the switch won't affect your key.

 

[KNBlazer]

http://gmtnation.com/f24/how-replace-ignition-switch-1766/

There are a couple of links that could be useful.