Hi I have a Mini Cooper 1.6 2005 I need to connect a wireless camera to the reverse light cable but could someone advice me which cables are the positive and negative to the reverse light please
You should have three different wires leading there. A Brown wire(ground). A Black with blue stripe(transmission). A Blue with yellow stripe(reverse control switch).
Keep in mind that the reverse control switch and transmission switch are independently Blue with yellow stripe. In other words. If that is how you have to hook this switch up to gain a purchase on the wire right after or as close as possible to the reverse light it's self. not trying to latch on before the two blue with yellow stripe wires are combined into a bigger one.
Or at least that is what the schematic shows. for 2006 and earlier models.
Do you have a DMM? If you do, you could split those two green wires and put one probe in each, then put the car into reverse. Go to the DMM and if the 12v has a negative sign in front of it, the positive probe is actually your negative wire, and your negative probe is your positive wire Speed Test .