Zitat:
Das ist doch nicht normal, oder?
Doch ist es. Wie meine Vorredner schon geschrieben haben. Da ich nicht zu Haus bin kann ich Dir erstmal nur englische Lektüre anbieten, aber auch die erklärt wie Deine Heckscheibenheizung funktioniert.
Defrosting phase:
After switching on the ignition , the rear window defogger is switched on when operated for the first time for 10 minutes or 17 minutes depending on the coding . Undervoltage monitoring is not active during this period of time.
Post-heating phase:
The post-heating phase starts up if the rear window defogger is activated once again after initial switch-on. Clocked operation of the post-heating phase switches the voltage supply for the rear window defogger relay at alternating intervals of 40 seconds ON and 80 seconds OFF.
Undervoltage monitoring:
Untervoltage cut-out is activeduring the post-heating phase . The terminal 30 voltage is evaluated in the control unit and the relay for the rear window defogger is switched off if the voltage drops below11.4 V . The time counter is stopped . The function indicator , however, does not go out. The relay for the rear window defogger is switched on again if the terminal 30 voltage reaches a value above 12.2 V . For this purpose, the threshold value must be applied for at least 1 second.
