why is my truck overheating?

What is your question?

truck overheats, I can stop and crack the lid on the reserve coolant tank and it sucks all the water out, I Can hear my fan come on and my truck starts to cool down. Or I can turn my truck off and on, and then I can hear the fan come on and it starts cooling off. No leaks, that I have found, replaced thermostat. Also, heater does not below hot air. Truck also has some kind of electrical issue that causes it to not crank sometimes.

What makes this problem better or worse?

turning off truck or cracking lid on reserve coolant tank .

How long has your 2009 Chevrolet Silverado 1500 had this problem?

2 weeks