Z4: Check Wire Between Diode Junction Box & Timer Module

With the ignition key in the OFF position, remove the center green diode strip from the diode junction box. Locate and disconnect the timer module connector. Measure the resistance of the Red/White wire between terminal No. 21 of the diode junction box connector and terminal No. 14 of the timer module connector. See WIRING DIAGRAMS  . Measure the resistance of the Red/White wire between terminal No. 14 of the timer module connector and ground. Is the resistance less than 5 ohms between the diode junction box and the timer module and greater than 10,000 ohms between the timer module and ground? If yes, replace the center green diode strip. If no, service the Red/White wire.