Black copper trailer wires

[lakelandterrier]

Been tracing back the trailer electrics fault I suffered last week.

On stripping back the 8 strand wire that connects the trailer lights (and lighting board) to the car, on top of the corrosion I found last week, the copper core of each cable is black, going some way back along the cable, even after cutting back about 8". Having wired up a new plug, the trailer lights (and lighting board when plugged into trailer are still U/S.

Lighting board plugged directing on car is fine

Does this black covering of the copper so far back mean the whole trailer cable is knackered & needs replacing?

Could the fault be anything other the suspect cable?

[beerbelly]

usualy still works when its gone black I suspect you may have another issue .can you plug another trailer board into the car to eliminate the car socket

[ShinyShoe]

Originally Posted by lakelandterrier

Lighting board plugged directing on car is fine

Is this a sort of extension lead that is on the trailer then you plug the board in?

Which end is black?

Personally I'd suspect the cable as a starting point...

[mikehhogg]

the blackening of the copper cores is normal enough and shouldn't present a problem. like another member said plug another light board in and start from there.Have you a socket a length of cable and another socket on the trailer.are you using a suzy to connect vehicle to trailer

[HDAV]

Maybe check the grounds and connections, have you done a continuity and impedance test on the cores?

[jeffstevens763@g]

cable shorted out ?

[spartacus]

Continuity test the wiring with a multimeter. Personally I'd strip the lot out and rewire with tinned cable.

[lakelandterrier]

Hi guys, thanks for replies.

If I didn't make it clear - when I plug the lighting board directly into the car, via the same susie I use for the trailer cable all is fine (now rejigged so I can do this and ignore the trailer lights altogether) .

The issue is on the cable from the trailer - trailer lights + lighting board - to the car. this is the line that is not working, and with the blackened copper inner wires.

No idea what "continuity and impedance test on the cores means" but thanks anyway - this is someone who failed physics O-level and never understood why if we know electricity actually flows - to + why circuit diagrams are built showing the flow+ to -!

Wiring & testing the plugs correctly is me pushing my electrical boundaries!

Is the next most simple thing to replace this cable and check the wires into the fitting as part of this electrical "adventure"?

[paintman]

It is possible one or more of the wires has corroded to the point it's either severed or the strands left can't carry the current required.
As nothing works I wonder if you have an earth problem.
Testing isn't difficult. Plenty of 'how tos' on youtube & the internet & multimeters aren't expensive.
If you don't want to test then rewiring is the only alternative.

[Pikey Dave]

Once the copper has corroded black, you’re on a road to nowhere. Bin it & start again. That’s why tinned copper is the only thing to use anywhere marine applications.

[mikew4]

Plenty on YouTube regarding continuity testing. For example: https://www.google.co.uk/search?q=continuity+test.

Multimeters with continuity check facility are cheap as chips these days.

Its not difficult, but equally, not for everyone. If you are not the sort of person to pick this stuff up from googling, all fine and nothing to be ashamed of, but suggest you get an automotive electrician on the case.

[Orwell boy]

if your not already ,convert to new style 13 pin trailer plugs ,they are far better product ,than the 7 pin ,imo, the thought that you missed the nacho run for a light board problem would be enough to throw the whole lot away and start again in my opinion .

[Pikey Dave]

Originally Posted by Orwell boy

if your not already ,convert to new style 13 pin trailer plugs ,they are far better product ,than the 7 pin ,imo, the thought that you missed the nacho run for a light board problem would be enough to throw the whole lot away and start again in my opinion .

^^^^^^^^
Wot he said

[lakelandterrier]

Originally Posted by Orwell boy

if your not already ,convert to new style 13 pin trailer plugs ,they are far better product ,than the 7 pin ,imo, the thought that you missed the nacho run for a light board problem would be enough to throw the whole lot away and start again in my opinion .

Agree - the issue is not the lighting board itself - it's the newfangled trailer lights -(or the cable that connects them (and the lighting board to the car)

I can now connect lighting board directly into car bypassing the trailer connections, so one level that's OK, but I need to sort the trailer lights.

As next step will replace the entire 8-strand cable with new. If that doesn't work points to a fault in the trailer light wiring along the trailer - but is all new (less than 3 years old and LED) Never dipped in water! All new learning

[HDAV]

Get a multimeter with continuity tester and a lengthy of wire...... touch the 2 probes it’s beeps.....this means the circuit is complete now use the probes to test pin 1 each end of trailer should beep (length of wore allows you to extend the probe)

Do pins 1-7 all should beep if good...... my guess is you may have side marker lights.... these use sidelight + ground..... my guess is a failed side marker or ground is dragging the whole assembly down....

Impedance test is same as continuity but measure the residence of the line for a short copper wire impedance should be negligee anything higher will cause issues..... look for a corroded or missing ground lug...


Cheaper online https://www.screwfix.com/p/lap-mas83...ter-600v/75337

[lakelandterrier]

Found the problem

It is the trailer light to lighting-board plug box....earth & 2 other wires worn through and come adrift

Considering there's no stress or tension on these wires and it's bolted to the trailer I'm a bit surprised, but will rewire with nice new cable and plug

It's not a connection I'd normally check not only is it a pig to access the way it was originally mounted on the trailer winch-post, but it's a connection I though would wear.

Oh well, bit more experience gained.

Thanks for the advice.

LT

[Bushrider]

Not working trailer electrics can be the PITA ..
I was also tired of having all the time trouble with non working lights and rewired recently the entire trailer .
After having very good experience with the trailer light on my Vanclaes trailer I converted the trailer of my SR6 as well to waterproof LED lights .
No light board anymore , installed a 12V LED adapter for the car CANBUS system , soldered all connections and sealed the 3 boxes with electronics potting compound .
The only open connections are in the 13pin plug which goes in the car .
Submersing the trailer is no issue anymore and no issues anymore with corroded connections .

[spartacus]

That Bushrider, is a thing of beauty!

Did you fancy LED marker lights on top of the wheel arches?

[Bushrider]

No - nothing on the wheel arches but all side markers are also LED .
As the trailer is now it is conform with the regulations in Germany .

[HDAV]

Originally Posted by lakelandterrier

Found the problem

It is the trailer light to lighting-board plug box....earth & 2 other wires worn through and come adrift

Considering there's no stress or tension on these wires and it's bolted to the trailer I'm a bit surprised, but will rewire with nice new cable and plug

It's not a connection I'd normally check not only is it a pig to access the way it was originally mounted on the trailer winch-post, but it's a connection I though would wear.

Oh well, bit more experience gained.

Thanks for the advice.

LT

Can’t tell from the image but stranded cables into a screw terminal should be ferruled........ and frankly shocked if that is a factory wiring job at the state of that.......there are even specific ferrules for doubles up cables.....
Just an ex apple (not check it’s the right size) https://uk.rs-online.com/web/p/crimp...rules/3117971/

Also having 2 cables going Into the plug/socket means the water proof seal is compromised so expect water ingress in future...... a 3 way JB should be used with appropriate grommets/glands I favour a wiska box https://www.tlc-direct.co.uk/Manufac...s_1/index.html do he joints in there properly glanded