I have a 2004 Mustang v6. It will crank but not start. The theft light is blinking fast without key in the ignition but when I turn key to run it goes out but still won't crank. I was told to turn ignition to run shut the doors and wait 10 minutes and it will reprogram, it worked once, then went back to not starting. Then I tried a different key and it worked for 5 or 6 times and now back to the same old thing. I was thinking maybe the transponder ring was not getting the signal to the module. Any thoughts???