Clutch problem

Recently my truck is having problems starting. It has a manual transmission. When turning the key, sometimes nothing happens. Sometimes it turns over about half a turn and then stops. Sometimes it starts right up. The battery is fine. But when I push the "clutch start cancel" button and do not press the clutch, it always starts as it should. It's almost like the clutch is freezing up somehow when it is pressed. The truck runs and drives fine. It only started a few weeks ago in the cold weather. Any ideas?

 

The clutch start switch probably just needs to be adjusted.

 

I have tried that. It checked out fine. I'm really puzzled. Maybe in the wiring?