Socket Pin Assignment
Pin
Circuit
1
Indicator lamp, left-hand side
2
Rear fog lamp
3
Ground (circuit 1-8)
4
Indicator lamp, right-hand side
5
Tail light, right-hand side
6
Stop lamp
7
Tail light, left-hand side
8
Back-up light
9
Constant plus
10
Charging line
11
Ground (circuit 10)
12
Trailer identification
13
Ground (circuit 9)
22
321 540 391 101 - 005 - 10/07
Installation Instructions:
Electrical System for Towing Hitch
Wire Colour
black/white
gray/blue
brown
black/green
gray/red
black/red
gray/black
black/blue
red
yellow
brown/white
--
brown
VW Golf A5