Trailer lights wont work.

[m3jappa]

I live a life of being in confusion on various things that go on

Latest one.

I had a trailer and all the lights on it worked.

I sold it.

Bought another one (second hand). Plugged the cable in and the only lights that work are the right indicator and the brake lights.

The guy i bought it off then plugged it in to his truck and they all worked. Must be your 13 to 7 pin adaptor playing up.


Tonight i went and got a new adaptor and a multimeter.

Basically both plugs show a 12v voltage reading for all light functions. `(i haven't plugged the trailer back in though as its not here, i admit theres a chance it might now work as perhaps connections weren't great? but it is slim as i messed about with the old plug while i had the trailer to no avail.)

So wtf is the problem. I hate problems like this as i find it hard to find someone who will even look at it let alone fix it. What could be the issue here?

[normalbloke]

Does the new trailer have LED lights? Does the tow vehicle have CANBUS?

[m3jappa]

normalbloke said:

Does the new trailer have LED lights? Does the tow vehicle have CANBUS?

Yes to led lights and the can bus i am not sure. It is a 2016 mitsubishi canter truck.

[m3jappa]

I still cant determine exactly what can bus is but i think it means it has warnings systems for stuff like lights. Which it does.

[General Price]

Get a 13 pin socket on your motor instead of messing about with the adapter.

[m3jappa]

I finally worked it out.

Got the very helpful canter manual out which showed all fuses and locations and found that theres a trailer light fuse and also a left and right trailer rear light fuses....
One had blown, which im guessing must have had an effect on the other one.

swapped them for new ones and hey presto lights now working.

The weak left indicator must have been a poor connection at the socket on the light as after removing it, giving it a little blow out and putting it back that now works too.

Result