Ford Repair: 1997 Ford thunderbird just stopped starting, vibration damper, catalytic convertors

Question
Hello,
I am looking for help with my 1997 ford thunderbird with the 4.6 engine. I parked the car yesterday went out to go to the store today and it wont start. No turn over at all no relay click nothing .Everything lights up battery is only 5 months old and shows a full charge.All terminals are clean but nothing. I turn the key and not even a relay click.I am looking at my Haynes book now looking for the exact starter relay location and will try to use a jumper and see what happens.Any ideas where to go from there besides yankin the starter yet? Only codes I show are for my catalytic convertors to be replaced as they are failed.Thanks in advance

Answer
Get a large breaker bar and socket on the vibration damper (big lower pully) and make sure you can turn the motor 720 degrees. This reminds me of a problem I recently worked on where the head gasket had leaked and water in the cylinder bent a connecting rod upon starting. The engine then reacted like yours. If you can't easily cycle your motor by hand you have problems. Disconnect the battery for safety.