trailer wiring

O.A.P

DSC_0047.jpg

I'm trying to add side lights to my trailer but splicing into the existing loom has me beaten. In the attached photo one of the six new side lights is shown plus how the tail lights have been wired up.
Its a seven pin plug but the Blue , green and brown wires are just taped up and not used at all?
I want the side lights to come on at night when I have lights on, so far by connecting to the black positive and red negative wire that works but when I press the brake they go out.
I have only noticed this now the existing wiring loom works fine during daylight but at night with lights on ,the indicators and brake lights flick on and off together plus the hazard lights are the dimmest excuse possible.
I think its been wired wrong from the start but I'm not sure, any help would be appreciated.

markkelly2

mgbgt1978

As shown above.
Your's looks like it was wired incorrectly, the yellow wire should not be feeding a double filament bulb for example. It's the L/H indicator so should only be connected to a single filament bulb along with a White earth....Your's looks like the guy used Black for the Earths.
Also the wiring diagram shown by Mark doesn't quite show you that the Red is Brake lights and the Brown/Black are tail lights.
If you already have proper 7-core trailer cable on the trailer then it's fairly easy to just rewire it as shown in the diagram.
Also check that whoever wired your car didn't just join the Brown and Black and connect them to just one tail light.
If you are adding four more tail lights then it would be better to have the Left and Right as separate circuits to avoid blowing a fuse.

O.A.P

mgbgt1978 wrote: »

As shown above.
Your's looks like it was wired incorrectly, the yellow wire should not be feeding a double filament bulb for example. It's the L/H indicator so should only be connected to a single filament bulb along with a White earth....Your's looks like the guy used Black for the Earths.
Also the wiring diagram shown by Mark doesn't quite show you that the Red is Brake lights and the Brown/Black are tail lights.
If you already have proper 7-core trailer cable on the trailer then it's fairly easy to just rewire it as shown in the diagram.
Also check that whoever wired your car didn't just join the Brown and Black and connect them to just one tail light.
If you are adding four more tail lights then it would be better to have the Left and Right as separate circuits to avoid blowing a fuse.

Thanks mg, he never used the brown wire at all apart from soldering an extension to it and two others and running them to the right tail light and then taping them up.

Man of Aran

A dedicated neg-ive return wire is essential as mentioned. Never depend on chassis earth return from a trailed device back to host via a hitch.
Strange symptoms of dim and blinking on other circuits is typical of alternate pathways being scavenged for earth.

O.A.P

Man of Aran wrote: »

A dedicated neg-ive return wire is essential as mentioned. Never depend on chassis earth return from a trailed device back to host via a hitch.
Strange symptoms of dim and blinking on other circuits is typical of alternate pathways being scavenged for earth.

You know more than me about it anyway, Mark Kellys diagram is straight forward enough to follow but Im not sure about the front marker bit is that a ground , earth, roof or sky thanks for any advice