having issues cranking 97 blazer when it is raining outside. It will turn over but not crank. When it is dry I only have slight issues. Doing research it looks like I need to replace the crankshaft positioner. Where is it located and how to you replace it?

 

This situation is more commonly associated with the distributor cap. Check it for cracks, carbon tracing, or being loose. I don't know about the '97s, but on some model years there is a small screen on the base plate of the distributor that can get debris on it and moisture will collect there, causing issues.