I have a 2004 F150 Heritage XL with a six cylinder and standard cab, manual windows and locks. I have an aftermarket alarm that unlocks the doors. The alarm is functioning properly and locks and unlocks the doors. When I put the key in the ignition all of the normal dash cluster lights illuminate and go out like normal. When I turn the key to crank the engine all the lights go out except the battery light and the seatbelt(haven't buckled the belt in a while). Absolutely nothing happens, no clicks, no engine turn over. When I let the key go, all of the lights come back on like normal. I have had both the starter and battery checked and both are fine. Need help please.