Troubleshooting earth problem - trailer lights

[ozscott]

Hi all,

My submersalites are set up so that from the plug there is about a metre and a half of standard 7 pin round cabling and then it Y's off - with the same cabling to left and right chassis rails and lights. It has worked well for years, but I just tapped into the power wire and earth wire on the right light for a little CMOS camera on the trailer - twisted, soldered and covered with that insulation tape that binds on itself.

As part of the process I had to move the loom from the front chassis rails and stuff them back in again (ie to get the Camera cabling back through to the car). Now all lights work except right hand indicator which causes the brake and parking bulbs to flash - so alternate flashing brake and parker and then indicator and so on.

I would not have thought that the camera being tapped in has caused insufficient earth, but maybe? The other option is to pull apart the earth join at the front Y where the loom diverges to the left and right lights and check the earth join there, but before I go upsetting all my nice waterproof joins can anyone shed some light (no pun intended).

Cheers

[Cheech]

I recently changed over to led lights. But had an earth issue. I think it was a problem further up the cable. Anyway, I realised I was only using 6 of the 7 wires, so I just swapped over the earth wire with the unused wire, and problem solved without having to replace the whole lot.

[Duckfish]

You'll probably be best run a seperate earth wire to your loom rather then trying to find the faulty connection. Not quite as messy and easier to do.
Duck

[Fed]

There's not usually a permanent 'power wire' on a trailer, are you trying to bring the camera on with the parking lights.
Trust no one when it comes to wire colours.

[ozscott]

Fed - thats it entirely mate. When the park lights are on the camera is on. The problem exists whether the camera is one (ie whether the park lights are on) or not...

Cheers

PS. I wired the lights on this trailer years ago using standard 7 pin round diagram from the Narva Au sight, so I am confident about the colours at least.

[Fed]

I think I'd pull it apart again Ozscott, if it all went wrong from when you did it then it has to be something you did. Well you'd think anyway.
Bloody electricity works with magic you know.

[ozscott]

Yep - I could start with the joins up at the goose neck join I suppose. I will do that and then run back from there. I could run a new wire for the earth, but I would have to cut into all my nice new sealed up wiring down at the light...so go with the easier one first.

Cheers

[robothefisho]

You could start by cleaning the trailer plug receiver with some contact cleaner. Then open up the plug and see if its still clean and proper. Then go hunting for problems with the wiring.

[ozscott]

Thanks Rob - good point. Will do that first, although the left side light, brake and parker all work as advertised - and at the plug end it shares the same earth wire as the right side. Will have a captain's though.

Cheers