I am a big fan of LEDs and I am determined to replace all of my car's filament bulbs to LEDs.

So far I have converted:

Headlamps (still experimenting with these)
Parking lights
Fog lights (Osram DRL / fog)
License plate lights
Internal lights (roof, footwells, boot, glovebox
Puddle lights
Hi-level brake light
Reversing lights

Now when it came to the stop / tail lights I encountered the dreaded canbus flicker on the tail lights (the brake 'filament' is fine) so I thought I would simply add a load resistor as so many websites will tell you. The general standard seems to be 6 Ohms so I connected a 6 ohm 50W resistor between the power and earth of the tail light and .... Voila! ..... everything worked fine. In the process of pondering where I should mount the resistor I had left the lights on for a few minutes and when I touched the load resistor it was so hot my skin sizzled and I got quite a nasty burn!!

Ohms law I states that a 6 Ohm resistor will pull 2 amps from a 12V supply and consume 24 Watts. I am trying to emulate (as far as canbus is concerned) a 5 watt bulb so does this mean I should increase the resistor value to something like 25 ohms to reduce the current and therefore also the heat? I am quite shocked at how much heat was being produced and if there are other people who have blindly connected these resistors to their new LED retrofits, I would not be surprised if someone's pride & joy has a fire! Cheers,
Raz
FL1 TD4 GS Auto 2001 Silver
FL2 TD4 Auto 2007 Black
FL2 XS SD4 Auto 2012 Fuji White

You obviously need to fool the system into thinking that a filament lamp is in place. The question is "what minimum current load is it expecting?" The 5W bulb will present a resistance of V^2/W ohms ie 144/5 or 28.8 ohms. The only way to find out the minimum is experiment with different resistor values (or borrow a variable resistance box) and see for yourself. Don't forget that the LED will be drawing some current too so perhaps 35 ohms will do. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Thanks for the excellent response Dorset - I have found some 33 ohm resistors on Fleabay so I will give them a try. Meanwhile I have connected 2 X 6 ohm resistors in series and these appear to run much cooler so I am definitely on the right track. It appears that anything over the LED equivalent of 5W does not upset the canbus because I have not found a need for load resistors anywhere else. Cheers,
Raz
FL1 TD4 GS Auto 2001 Silver
FL2 TD4 Auto 2007 Black
FL2 XS SD4 Auto 2012 Fuji White

I'm not sure why if my 14my has canbus it doesn't show a bulb out warning on the display when the 1st headlight bulb blew followed by the 2nd - still not replaced (not arrived in post yet?) so no headlights working and no warnings?