A picture for your efforts.

This morning(2°F) I went to start my Caprice and all I get is a click. I have power, and the battery reads 12.5v. I attempted the tapping of the starter with a hammer trick too no avail. Also tried a jump pack.

My first thoughts were a failed starter solenoid, but when I tried again in the afternoon, now a sweltering 25°F, it fired right up. A co-worker suggested the cold affected it somehow, but I've never heard of that happening. Hopefully a fluke event, but any input is appreciated. Thanks.