Well first off I thank you for reading this, and any input would be greatly appreciated. I just finished up a trip from ok. to tx. and back. I parked my truck went to bed, and when I returned to the truck the following morning it wouldnt turn over. I opened the fuse box, and the relays are clicking, but it wont crank. I checked the voltage on the batteries, and they are both 12.4. They were a little corroded, so I cleaned both of them, and still nothing. The air lights, blinkers, and everything else still works, but no crank click or anything. I left a power inverter plugged in to the auxillary cig lighter port. Could it be the starter? it has never given me any trouble in the past. Thank you for any and all advice on how I could troubleshoot this. I am mechanically challenged.