13 pin, #9 gets it own 12V from 11D/A4 fuse.
TRM input PDF shows signals in only to TRM, no connector A out signal to trailer connector.
Looking in VIDA parts, #1 harness 4, 7, 13 pin, #13 brain and #19 SW are all different.
I do not know if you can change/modify what you have now.
13 pin harness install PDF may be helpful.
Cable harness towbar
Fig. Description Qty. PS Part number
1 Wiring harness 1.00 31324671 7-POLE, CH -146100
Wiring harness 1.00 31346065 4/7-POLE, CH 146101-
Wiring harness 1.00 31346526 13-POLE, CH -146100
Wiring harness 1.00 31373184 CH 146101-192227, 13-POLE
Wiring harness 1.00 31414859 CH 192228-, 13-POLE
2 Six point socket screw 3.00 986204
3 Cable tie 4.00 983750
4 Flange screw 1.00 999231 M6x14
5 Flange nut 3.00 985857 M5x5
6 Fuse 1.00 966329 15A, 13-POLE
7 Wiring harness 1.00 31324673 4-POLE, CH -146100
8 Protecting casing 1.00 8698871 (CA), (US)
9 Cable tie 2.00 983750 67 mm
10 Lock nut 2.00 985884 M4x6
11 Flange screw 1.00 999231 M6x14
Cross recessed screw 2.00 987054 M4x30
12 Retaining clip 1.00 8698082 (CA), (US)
13 Control unit 1.00 31350479 CH -182608
For vehicles with chassis number V70 CH-249100/ XC70 CH -146100, adapter wiring 31346554 and wiring 31373184 must also be ordered (EXCL US).
For vehicles with chassis number up to V70 CH -249100/XC70 CH -146100 new adapter wiring 31346554 and adapter 31373258 must be ordered (US).
Control unit 1.00 31407107 CH 182609-
14 Tape 2.00 30698685
15 Adapter 1.00 31324330 7/13-POLE
16 Adapter, double-acting output 1.00 31324541 13/7-POLE
17 Adapter 1.00 8685525 13/7-POLE
18 Wiring harness 1.00 31346554 CH 146101- Extension
Wiring harness 1.00 31373258 4-POLE Extension
19 Towing hook 7-pol app 1.00 SW 30744322
Power supply 7-pol 1.00 SW 30744323
Fog light rear 7-pol appl 1.00 SW 30744324
Reversing light 7-pol 1.00 SW 30744325
Towing hook 13-pol app 1.00 SW 30744326
Towing hook 4-pol app 1.00 SW 30744327
TRM remove 1.00 SW 30744328
TRM reload 1.00 SW 30744330
Towing hook 4/7-pol app 1.00 SW 31350003
Note! The trailer module (TRM) must be programmed with software in order to function correctly.
Position – Function
1 – Left indicator lamps
2 – Rear fog lamp
3 – Ground
4 – Right indicator lamps
5 Rear parking lamps, right
6 – Brake lamp
7 Rear parking lamps, left
8 – Reversing lamp
9 – Power supply +12V
10 – Charging +12V, only with the ignition switched on.
11 – Ground
12 – Not used
13 – Ground