will turn over, but won't start. any help?
no power to the coil, no power to the pcm, no power to obd-2 plug, and all fuses and relays are good.

 

Could be the 3 to 1 splice under the power distribution box. There is a write up on it in the FAQ 1. I've had the same problem before, and never really figured it out. My problem wasn't the splice though. I ended up replacing the throttle position sensor, and idle air control. I would check your grounds also, and re-set your ECM by disconnecting the neg. battery cable and turning the key on (the spot before turning over the engine) for 20 sec. All I know is my truck is like a woman..... very temperamental. If it starts after re-setting the computer than you know it's a sensor, or something electrical. I'm a novice to these trucks though. Good Luck!

Edit: Check your CEL codes too. There is also a write up on this in the FAQ.