I guess "Electrical" issues

I have a 2004 F-150 4.6L V8. It runs fine... when it starts. I will turn the key and the engine sounds like it is about to start, but doesn't fully turn over and complete the start. I don't have any dim lights and the battery is less then a year old.
After reading other forums, I tried hitting the auto door locks with clicker sitting inside the truck and the truck fired right up like normal... What is wrong this? Is it an easy/simple/cheap fix?