Thread: LED Adaptor Module

Companies that make these devices over complicate the solution.
I built a box on the A frame of my caravan and put high wattage resistors across the tail, stop and blinker wires. I used resistor values that are equal to the resistance of the incandescent globes. ie 10W tail lamp ~ 15ohms. 21W Stop/Blinker ~ 7ohms. So for the tail lamp 16ohms 10W and for the others 8ohms 25W will do. If you get the proper power resistors you won't need a heatsink.

Originally Posted by superhet

Companies that make these devices over complicate the solution.
I built a box on the A frame of my caravan and put high wattage resistors across the tail, stop and blinker wires. I used resistor values that are equal to the resistance of the incandescent globes. ie 10W tail lamp ~ 15ohms. 21W Stop/Blinker ~ 7ohms. So for the tail lamp 16ohms 10W and for the others 8ohms 25W will do. If you get the proper power resistors you won't need a heatsink.

You over complicated the solution for a D4.
At the minimum you only need to put a resistor on one of the indicator circuits, the D4 will recognise that a trailer is attached but you’ll only get the trailer icon flashing on the dash when you use the indicator with the resistor attached.
For symmetry you fit a resistor to both indicator circuits.

I put a resistor in the right indicator circuit in my round to flat adapter. Riveted it to the adapter, no heat sink. Works fine.

I went with the LED adapter on my 2013 D4 way back in 2013.
Yes, I probably paid more than I needed to or should have, but wth, it works fine with the flick of a switch.
Went with what I thought was best and easiest at the time. Have had no issues so am happy.

Thanks for the heads up I did not attempt to dissolve the potting compound. I measured the resistance values between the indicator connections (green and yellow) and ground and came up with values of 7.1 ohms. Terminated all other incoming and outgoing connections except the incoming green, yellow and white wires on the module and connected the wires in parallel into the trailer wiring harness. This resulted in the dash displaying the trailer symbol if either indicator direction or the Hazard Lights were selected.

To automate the switching of the module I connected a 12V lighting relay into the earthing wiring of of the module. I use the NC contacts on the relay, connected the NC reed switch on the Narva Trailer Socket to the coil powered from an ignition switched 12V supply.

This process means that the module resistors are only connected to ground when the socket reed switch is opened by connection of the trailer plug. Only disadvantage with this system is that the switching relay is continually energised whilst there is no trailer plug in the socket, I will evaluate if I can reverse the switching logic.

Originally Posted by RHS58

I went with the LED adapter on my 2013 D4 way back in 2013.
Yes, I probably paid more than I needed to or should have, but wth, it works fine with the flick of a switch.
Went with what I thought was best and easiest at the time. Have had no issues so am happy.

Same.
I purchased one and it works fine, placed in LHR pocket near vehicle jack.
The owner of LED actually owned a nice looking black D4 HSE.
Being fundamentally lazy, I leave my switch "on" all the time and simply watch the Trailer Light on the dash flash when ever I use indicators with or without a trailer coupled.

Originally Posted by Discodicky

Being fundamentally lazy, I leave my switch "on" all the time and simply watch the Trailer Light on the dash flash when ever I use indicators with or without a trailer coupled.

Probably not a good idea as the car assumes there is a trailer and adjusts all sorts of settings to allow for it.

Originally Posted by DieselLSE

Probably not a good idea as the car assumes there is a trailer and adjusts all sorts of settings to allow for it.

That's interesting!
It hadn't occurred to me that it would be the case. I assumed it would only make adjustments to settings when I connected the trailer electrical coupling.
Many thanks for that!