I have a complete rear defogger system for a '69 Firebird with the switch, motor, grille, and harness... BUT! The harness looks incomplete since only one purple wire is running from the switch to the motor on the package tray. Can anyone post a pic or wiring diagram of how it is supposed to look please? I think I am missing one wire from front to rear that runs along with the long purple wire and maybe connects to a resistor of some type to make it a LOW and HIGH wire? Any help is appreciated. Thanks in advance!