Planning the next
AO Silver Member
Join Date: May 2007
Location: United Kingdom
Brake lights : there are two feeds from the fusebox to the brake lights. ( The output of the brake light switch goes back to the fusebox and exits there in two wires ). The high level light is fed off the feed to the right side brake light. So, if the HL lights are working, it argues that at least for the right hand side everything is fine up to the boot.
In the first instance, I would test for continuity between the HL light unit and the right hand side bulb holder of the main light strip ( remove the bulb for the test! ). You're looking for the Red/Black wire at both ends. You say you've measured volts so presumably you have a multimeter to test for continuity ...
It is somewhat unlikely to be an earth problem as all the rear lights, according to the manual, use the same earthing point. However, if the black/red wire shows continuity, then test the other side of the bulb holder to earth by measuring from the bulb holder to the car body ( again with the bulb removed ). Repeat this earth test for the left side bulb.
I'd concentrate first on the right side as you know the supply is good into the boot area and measuring continuity for the left side is more problematic. My suspicion is that you have a wiring fault in the region of the rear light unit and fixing the right side will also fix the left side.
Heater fan : Does the car have aircon or not?