[GCncsuHD]

Before you tear into all that, I would check for a loose or corroded battery connection. A bad connection can let just enough current through to power lights/radio etc, but too much resistance for the starter to even so much as click the solenoid. And with the fluctuating temperatures lately it is highly likely it can have a good connection when warm and a bad connection when cold and vice versa.

If when you are having this issue, you pop the hood and jiggle the cables and it fixes it (temporarily) that is your issue, although sometimes the can be tight but corroded and this test will not work.