As a mechanic i will tell you the international color chart:
Yellow = left indicator
Green = right indicator
White/black = earth
Brown = tail lights/side marker lights
Red = brake lights

If you have any problems send me a pm and if you live not to far away of me i could pop out and give you a hand.Lots of people have trouble with trailer lights so there fore i am currently trying to work out how to have a wireless trailer lights all done by infared signals from a box mounted in your boot.

I rewired my boat trailer a few years ago. It used to have those Australian "Submersalites" which quite frankly I thought were useless as they leaked badly and needed attention for every WoF.

I replaced them with the Trojan LEDs which are sealed with the cable attached at the factory. I ran these cables and separate cables for the side lights to a connector strip which I mounted under the winch as high as possible. From the connector strip I ran the lead to the car. This lead is long enough to clip under the winch post too when not hooked up to the car.

The result is that the wiring is all sealed with all the connections staying 100% dry when beach launching with a tractor. Lowest vulnerable points are the side lights on top of the guards. If they ever give me any grief I'll chuck them out and replace with LEDs.

So far I've not had a single issue which has been great.

Just did the same as Dagwood for pretty much the same reason.  Had to get my supposedly-submersible trailer lights serviced to get a WOF about 2 months ago.  Have used the boat about 3 times since then and when I hooked up last weekend one of the indicators was out again.  Decided "sod-it" and went out and got a set of the Trojan LED jobs and hooked them up via a connector strip in pretty much the same way as Dagwood has.

thanks for the feedback guys and for your offer snapper shagger- I really appreciate that. I will have a go myself but may hold the offer in reserve if that is OK- I will get on to the process of elimination and now need to set up a lave battery etc as CEEBEE described

Cheers

Jim

A mate and I recently rewired my boat trailer lights (they are on removable uprights which slot into the rear of the trailer for towing).  What we did was to run a single 5 core wire from the connector on the car to to a connector on top of the right hand mudguard and then to the right rear tail light; we ran another cable from the left rear tail light - this cable fits into open loops welded across the back of the trailer - then we fitted individual wires to the existing right hand tail light to make the 'bridge' for the wires which activate the other tail light and made the necessary connections outside of the back of the right hand tail light and sealed it all with heat shrink tube. 
In this way if there is ever a problem with the wiring, the first place to look at to fix this will be at the connection behind the right hand tail light...and there is no need to remove the tail light covers at all.
When I take the lights off the trailer prior to launching the boat it is a simple matter to unplug the connector on the mudguard, unclip each tail light and its' upright from the back of the trailer and the whole lot goes into the boot of the car.  Easy peasy....

Same problems for me as well constant issues with submeralights got them all going again yesterday (25 knott days are good for trailer maintenance) for the last time have ordered a set of LEDs from WR industries in Warkworth  ($100 a pair Brett imports them himself from overseas) will fit them next windy day and will let you all know how they go .

Hello guys the $100 LEDs turned up and fine looking lights they were too. However they were only 12V not dual voltage. The supplier kindly let me return them and promptly refunded my money,awesome service. So I bought some Trojan ones from REPCO they had them on special in their mailer, for those of you who live in Auckland , Smart Marine has them for REPCOS sale price all the time $150. Any how wired them all up on Saturday piece of cake and they look like the Ducks nuts bolted in the back of the old hoskings . 

ive replaced 2  in the last 2 weeks, they still the best option i rekon

dunno mate - just karked it, nothing is immune to salt water - they are most defently the best option tho - just so easy to maintain - no bulbs, no poxy earth issues etc etc..ive started putting a little bead of clear silicone around where the cable goes into the unit..just that little extra for vibration etc

did you get them sorted Jim or not??