Need a diagram with colour codes.
The colour codes are there as are cable run distances within the loom, but apologies for quality of image. The style of drawing doesn't indicate exact routing or circuits but I found it adequate when tracing reverse light switch wiring.
Examples of colour codes:
GN - green/brown
RW - red/white
GP - green/purple
WG - white/green ...........
In fact for the most part they follow
this convention.
If you have need of a better quality wiring image, PM me with your email address and I will attach original.