drove it yesterday no problems. got in this morning tried to start and would not turn over. thought it was a dead battery. Ran jumper cables to my wifes car waited for a while tried again. nothing. bought a new battery put it in. Nothing. I did notice when turning the key the dash lights come on then half a second they go out. interior lights, and 12v outlet work but no headlights. any Ideas other than the obvious corroded terminals or loose terminal wires?

 

just checked all relays still nothing.

 

grab your jumper cables & see if the headlights come on when you jump from negative battery post to engine block.
This is how I found a bad battery cable on my Ranger.