7 Pin Flat Plug and Socket

There are two basic types of electrical plug and socket connectors for light trailer use - one is round and the other flat. The 7 pin flat connector is generally more robust than its round 7 pin cousin, which being round - may be damaged or pulled out easier. Flat plug and sockets are also known as Type 3 connectors and come in 7 pin and 12 pin.

As mentioned earlier for 7 pin connectors, if interchangeability problems arise, then it is recommended that pin number 5 in the 7 pin connectors be used only for service brakes, although if auxiliary circuits are required, then the 12 pin Type 3 connector would be preferable.

• Pin 1 - Yellow - Left-hand turn indicator


• Pin 2 - Black - Reversing signal


• Pin 3 - White - Earth return


• Pin 4 - Green - Right-hand turn indicator


• Pin 5 - Blue - Service brakes


• Pin 6 - Red - Stop lamps


• Pin 7 - Brown - Rear lamps, clearance and side marker lamps