A6 Quattro Sedan V8-4.2L (BVJ) (2007)
On V6 engines, you need to be sure not to switch the red and green wires between relays.
17. Connect adapter harness wire (Figure 14, 4) to coolant fan fuse S42.
18. Connect adapter harness wire (Figure 14, 5) to second speed coolant fan fuse S104.
Tip: Interchanging wires 4 and 5 does not affect function.