Hi all

So this weekend consisted of rewiring my ifor williams ct177 trailer however I'm a bit lost at present with the led lights. I've rewired it all from one end to the other so fresh 7core wire, new junction box, and new wiring to each light.

The part I'm stuck on is the following

When you turn the indicator on left or right, it works with no trouble with the exception of the hyper flash which I expected.

Soon as I turn the side lights on and press the indicator, both indicators light up with the dipped red light and the indicator lights up on both side with a pulsing look so it's always on like the side light is always on which I can't seem to get past.


Soon as you turn the lights on manually with a battery to the plug, they all work fine so I'm guessing it's the car over powering them and keeping them on.

I've got a device called an led master. Soon as that's in place, the indicators work with no trouble but I don't have any side lights

That's the pain with LED trailer lights.
The vehicle expects to sense tungsten bulb currents and gets confused.
The car transporter works fine, but the caravan is fitted with LEDs and caused problems.
The 'magic box' that was supposed to fool the car into thinking it could see tungsten bulbs only partially solved the problem.
I fitted dummy resistors in parallel with the LEDs and problem solved.

Eventually, manufacturers will get it sorted. (Rosy glasses in action) Forty years of progress. 1972-2012

Mine was originally the normal bulb type but the trailer needed rewiring so picked up the lights as well. Sounds like that's worth a shot tho trying some resistors I guess as genuine ifor williams led lights are £280 so don't really fancy coughing that price if I can help it considering the trailer gets used maybe 5 times a year

If they were tungsten, I’d say you had a bad earth. I’d still check that. Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Where would a dodgy earth start from on the vehicle mate?

All sorted at long last

Nice! Well done. And that is a great trailer made even better now

Cheers mate. I'm in trying to work out if I should sell it or not tbh. Turns out the £70 ifor williams led lights was causing the issues with the Christmas tree lights so tried an amazon £20 special and it works perfect. As they say less is more so double stacked them on both sides too make it look better. Even found time to do the 4 marker lights as well so pretty happy with the results

Click image to enlarge

Click image to enlarge

Cracking job and you saved yourself a fortune.

That is some trailer!! if you hadn't said it was an Ifor Williams, I would have expected the maker's ID plate to have included the name Isambard.

Cheers mate. I spoke to a few places and they said I'm looking at 10 hours labour to rewire it. Took me about 15 hours to do it but I was also having to go out and get parts but it's not a hard job. Just could be made a lot more easier if I had some ramps or hi lift axle stands. It's a decent trailer and it's done me well. I'm just in-between two minds of selling it or keeping it.