I have a 2002 F150 5 speed with a V6. After replacing the alternator, I've been experiencing a strange elecrical problem. After turning the engine off, the indicator lights, as well as the odometer stay lit. even with the ignition completely off and the key out. Sometimes it will crank but not start. Disconnecting the battery and re-connecting it will reset it and it will then start, however after turning it off for a few minutes it starts acting up again. Does anyone know what's going on? Could I have installed defective alternator?
Thanks in advance for your help
Pat

 

Do you or did the previous owner have an alarm installed? Does it have the keyless entry with a keychain remote?