Boat-trailer-part and wiring-a-boat-trailer – What you need to know

About UK/European Boat-Trailer-Wiring Codes

The most common boat-trailer-part to fail is the boat trailer electrical system. It is subject to water ingress into light fittings and lighting connectors. Also this has the effect of rotting out the copper electrical cables so they tend to need rewiring on a regular basis.

The next most common failure point are the wheel bearings, subject to salt water ingress and corrosion as they sit in the back yard for long periods and tend to seizes up. Initially the balls corrode at the contact point with the race and when used the material flakes off, the heat is then generated with the friction and ultimately the bearing grease runs out and the bearing fails

The UK and Europe use ISO Standards with two 7 pin plugs.

12N Socket Standard

1 (L) – Yellow - Left hand indicator light

2 (54G) – Blue - Rear fog light

3 (31) – White - Ground/earth

4 (R) – Green - Right hand indicator light

5 (58R) – Brown - RHS Tail/Licence plate light

6 (54) – Red - Stop (Brake) light

7 (58L) – Black - LHS Tail/Licence plate light

12S Socket Supplementary

1 Yellow - Reverse Light or Brake System

2 Blue - Spare

3 White - Return for Pin 4

4 Green - Power Auxiliaries/Battery

5 Brown - Warning Lamp

6 Red - Refrigerator

7 Black - Return for Pin 6

Faulty parts on your boat trailer? Get the right boat-trailer-part. All about boat-trailer-part and wiring and a lot more