The rear window demister and signal horns are covered in tracks 211 to 224. Yes, a Golf has horns. Especially a GTI.The rear window demister switch (E15) is monitored and illuminated via J-DC. As the wiring to the switch no longer directly has to carry the current to heat the rear window, the cable sizes can be reduced down to a lithe dimension.
E15 is illuminated (L39) and it has a tell-tale light (K10) to indicate when it’s running. The tell-tale could be set to blink when the heater’s been left on for a while.
Heavy lifting of driving the heating element (Z1) that is the rear demister, is done by J-TG. Monitoring the current allows J-TG to infer a temperature and to switch off supply when it’s toasty warm. J-DC could sense that state and start blinking K10.
The substantial difference in wiring is that the chassis connection for Z1 goes via J-TG; first reason being to minimise the number of wires but there’s also the possibility of using the element to brake the rear window wiper motor into its parked position.
J-Front drives the horns at the front of the car. J-DC will pick up the horn button signal. Details to follow.