Trailer Electrical Issue

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

Heres one for you...
I've borrowed mum and dads trailer.

When I plug the trailer into my car, I have 12v at the plug, but no lights.
When I plug it into mums car, there are lights.

Definitely no issue with the socket on my car. Checked by the Toyota dealer in a service today.

A conundrum...

Any suggestions?

[Hally Senior Member Find all posts View Profile Close Hally]

Check the earth very rare but lights could be earthed through plug rather than trailer.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

Perhaps a non-standard socket (wiring) on your Mum's car and trailer wired to match ?

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

They did work on mine about a month ago...

[Hogey66 Senior Member Find all posts View Profile Close Hogey66]

Have you tried someone else's trailer on your vehicle, or mums trailer on a different vehicle.

[foxclan Avid PP Poster! Find all posts View Profile Close foxclan]

In the 120 series jack storage compartment, the trailer wiring loom is connected to the vehicle loom.
I have had issues when the earth connection had not been reinstalled after doing some wiring mod back there.
Cheers
Troy

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

Have you tried someone else's trailer on your vehicle, or mums trailer on a different vehicle.

I haven't yet. But, I can say that Toyota had a set of lights to plug in and check, and all worked. It just seems to be this trailer and my car.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

In the 120 series jack storage compartment, the trailer wiring loom is connected to the vehicle loom.
I have had issues when the earth connection had not been reinstalled after doing some wiring mod back there.
Cheers
Troy

I'll check it out (I'm fairly certain it's the same in the 150). I've not been fiddling in that hidey hole recently though.

[Hogey66 Senior Member Find all posts View Profile Close Hogey66]

Maybe try spreading the pins on the trailer plug with a small flat screwdriver. I had intermittent trouble with mine a few months back so did this and all been fine since. Socket on your car may be a bit loose, worn, dirty and not making good contact.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

Maybe try spreading the pins on the trailer plug with a small flat screwdriver. I had intermittent trouble with mine a few months back so did this and all been fine since. Socket on your car may be a bit loose, worn, dirty and not making good contact.

Already done. I'm picking up power in the trailer's plug (I had it pulled apart with the multimeter in hand), just nothing at the actual lights.

[Hogey66 Senior Member Find all posts View Profile Close Hogey66]

Try using a test light rather than a multimeter. Bad connection can show up ok with a multimeter but will break down under load of a test lamp.

[MacroP Member Find all posts View Profile Close MacroP]

I seem to remember having the same or similar issue a few years back when I (ironically) borrowed my folk's trailer too. Lights worked fine on the old man's car but not on my car yet I've used many trailers/boats etc etc in the past with no issues. I was confident my car was fine. I used my multimeter to test so I was scratching my head.

What I found, from memory, was the trailer earth was broken somewhere. I cant remember if the break was at the plug or in the cable back to the lights. In the old man's Hilux, the trailer lights had been grounding back through the towball and towbar so had not noticed an issue and were working fine in his case though not in my case. Mostly likely didn't work in mine because of my setup is a removable hitch and not a good grounding path. The old man's Hilux was a simple towbar with a ball.

A simple test would be to try plugging in the trailer in to your parents car without the trailer physically connected to the towball removing the return path.

Hope that helps.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

I seem to remember having the same or similar issue a few years back when I (ironically) borrowed my folk's trailer too. Lights worked fine on the old man's car but not on my car yet I've used many trailers/boats etc etc in the past with no issues. I was confident my car was fine. I used my multimeter to test so I was scratching my head.

What I found, from memory, was the trailer earth was broken somewhere. I cant remember if the break was at the plug or in the cable back to the lights. In the old man's Hilux, the trailer lights had been grounding back through the towball and towbar so had not noticed an issue and were working fine in his case though not in my case. Mostly likely didn't work in mine because of my setup is a removable hitch and not a good grounding path. The old man's Hilux was a simple towbar with a ball.

A simple test would be to try plugging in the trailer in to your parents car without the trailer physically connected to the towball removing the return path.

Hope that helps.

There's an option...Ill get them to pop around and try that!

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

Try using a test light rather than a multimeter. Bad connection can show up ok with a multimeter but will break down under load of a test lamp.

I have been looking for an excuse to get myself a test light...