If you have a trailer or rear mounted bike rack and it obscures the vehicles rear lights and license plate, then you will need a light board, or you could be breaking the law?
You can either get some extra lights fitted by a garage or towbar specialist, or you can fit a socket or connector to the vehicle yourself…
The section below ‘Quick Overview‘ is a short summary of what’s required to fit a trailer or bike rack connector.
…and contains the following sections:
More detailed descriptions can be found in the following articles:
What parts are needed:
Note: Dependant on what you buy, sometimes wire is supplied with the product.
A trailer socket usually conforms to a specification, dependant on which part of the world you live in. The most important thing is to check what’s fitted to the trailer, or bike rack you intend to use (see)…
Normally a pressed steel bracket shaped to take the trailer socket, with all the mounting holes pre-drilled. This usually bolts to the towbar. If a towbar isn’t fitted, then an additional bracket may be required.
A mounting bracket with an open slot is preferable, as this allows the trailer socket to be removed from the bracket without disconnecting the wiring.
The bypass relay (The interface to the vehicle’s electronics) acts as an isolator between the tow bar electrics and the vehicle’s electronics. The bypass relay is actually one or more relays. Typically, a bypass relay is described by the number of ‘way’s’ it has. I.e. 1 way, 2 way, 4 way, 7 way, etc.
|No. of Ways||It controls the…|
|1 way||A single light, or set of lights.|
|7 Way||Rear lights (pair).|
|Rear brake lights (pair).|
|Rear left indicator (single).|
|Rear right indicator (single).|
|Number plate light(s).|
Note: Wire can be purchased as a single trailer light board cable with all the individual colour coded cables within, which may make life easier.