Ok, i have the same problem here with my 2004 GTP. I checked all the electrical circuits with my DMM, the voltage and resistance is within spec on the starter circuit and battery. I've replaced the starter itself, tested the P/N safety switch, and tested the Ignition switch and all are working fine. I've even pulled the spark plugs one by one to see if maybe my luck was bad enough I had a Hydrolock in a cylinder but that wasn't the case. Everything acts normal but the engine will not rotate at all. I'm going to buy a breaker bar and socket today to try and rotate the motor by hand but aside from that does anyone have any more ideas? I really don't want to call an expensive tow-truck...