AP4: Check Diode Junction Box Ground
With the ignition key in the OFF position, disconnect the bottom green diode strip from the diode junction box. Measure the resistance of the Black/Red wire between terminal No. 28 of the diode junction box and ground. See WIRING DIAGRAMS . Is the resistance less than 5 ohms? If yes, replace the bottom green diode strip. If no, service the Black/Red and/or Black wire.