Chevrolet Repair: 2004 Tahoe Z71 - no start / below Freezing, 2004 tahoe z71, 5k miles

Question
I have a 2004 Tahoe Z71 - I purchased brand new -maybe 5K miles on it. The car will not start when the overnight temp drops below 20 degrees or so? Lights come on - radio, tried jumping, etc.. Battery is fine - truck will start eventually - after "warming-up" in the sun - no sound at all when you turn the key? What could be causing this? Has done this 4 times this winter - finally going into our local dealer for a check-up next week - BUT - over the phone, they do not have a clue?  Any Thoughts?

THANKS!

Answer
Hi Peter, As you know having the problem happen to the tech is always a plus. The only thing that comes to mind is the ignition switch itself. Be sure that they replace this part if they don't find anything. If they do nothing then your still at square one, if they replace something at least you know it's not that if it still happens.

Sorry I can't be more help on this one

Mark