Trailer brake light warning
 

When I hook up my trailer to my factory fitted retractable towbar (V90) I get as warning that the trailer brake lights are not working, but they are!

Any easy fix?

Hello are your trailer lights LED ? , if so the car will not detect a high enough current draw & trigger a false error message . Also try connecting to another trailer / caravan & see if that remedies the issue .

Brake Lights
 

I would point out that i have the Volvo ECU in my car and have no issues with any lights the caravan is a 2 year old Swift Elegance all round LEDS. I would suggest there is a fault in the system.

You sure the road lights are led? My coachman vip has led running lights but indicator and stop tail lights are filament bulbs. Makes changing them and staying legal easy.

If all lights are led get hold of, beg borrow or steal, a trailer board with filament bulbs and try that, if the system now works you need resistors in series with the led lamps to increase the current draw.

I keep a known working trailer board carefully stored in the attic for just such testing. It is far easier to remove bulbs from a trailer board to enature failer warnings are working as they should than potch about with the caravans.

Paul.

Hi

Think that should be "in parallel" not "series" to increase the current flow.

Iain

A stop or indicator lamp is normally 21w

21w/12v= just shy of 2A circuit current.
A lot of led lamps will not stand that current through them so connecting a resistor in parallel so that it shunts the led lamps but gives a circuit current of 2A will work. Problem is the current will try to take the path of least resistance so the led lamps may suffer either way.

I have never measured the resistance of an led, reverse polarity they are open circuit correct polarity no idea.

Paul.

Hi

Section in the link below covers it

https://www.autobulbsdirect.co.uk/bl...ix-with-video/

Iain

I'm 99% certain that all Volvo 13 pin trailer setups are compatible with LED trailer lights. I did have a problem on my 2016 XC60 with factory towbar where it was randomly reporting bulb failures, this was fixed by using a genuine Volvo 13-pin to 7-pin adapter which I found strange but it did fix it, and the fault returned when I re-installed the chinese one from e-bay.

Mmmm, worrying as technically volvo are now Chinese, Geely finance owning a big part of them.

I find I have to change the 7N socket on the LandRover frequently, one of the costs of wadding the vehicle and submerging the socket. Decent quality lasts far longer than cheap Chinese even if the decent quality comes from China. .

Paul.

Trailer light warning on dashboard
 

Hi guys I have a warning light on my dash saying trailer light out but I don’t have a trailer fitted anyone else had this problem


Regards

Jason