Converting standard rear/tail & indicator lights to LEDs....advice required please

Perhaps not. Bobbin Mans light fitting is the one I would buy.

(Apologies for multiple similar postings, I was side-swiping on the Macbook to go back/forth and repost instead of the proper way).
 
Why oh why make so complicated the unit is shared across a number of bikes and years, the important bit is the adaptor cable at roughly £44 bobbin's light will fit and that's it done.
 
Why oh why make so complicated the unit is shared across a number of bikes and years, the important bit is the adaptor cable at roughly £44 bobbin's light will fit and that's it done.

Just wanted to clarify, that was all...calm down dear.....:D
 
Bloomin' ek :eek: I pop out to the station to collect my daughter and the thread's gained nearly another page!

Received your mail Keith, I'll pop it in the post on Monday :thumb2

Stu.
 
And god bless both of those!!

Right....that just leaves the adaptor cable......want to find me one of those too Adam to save me a job? ;)

No. Get off your lazy arse and do your own legwork, then when you have made up a kit put all the info on here as a reference for future use by others. :D
 
Is this what you are referring to ? on eBay item no. 171496696215
There are two size of spade connectors apparently. Must be a small resistor in the wiring to create a load to fool the system that the lamp is on.
Or am I talking a load of non electrical garbage. Can't some electrical wizard work out what the resistor size needs to be so we could make them up ?
 
That lead doesn't have the plug needed to connect the LED light unit, unless the original non-LED takes the same plug and it can be butchered although somehow I doubt it. I recall the conversion lead I bought from Motorworks fitted correctly at the light end but didn't fit the existing wiring on my bike ('06 GS), I think there were just 3 wires to connect though ... -ve, +ve tail light, +ve brake light.

Stu.
 
A resistor is about 10p how 3 bits of wire some crimp on plugs n bit of solder can cost between £20-40 odd is just rediculus :blast

I'll google it later prob info to make a lead around somewhere ;)
 
Converting standard rear/tail & indicator lights to LEDs....advice required p...

Found this, need to read and understand it !

Time for some mathmatics when fitting load resistors to balance the electrical load back up to the level the car expects when it is was originally fitted with bulbs.

First off is OHMS Law, not difficult:

V=IxR
I=V/R
R=V/I

V= Volts, I = Amps, R = Ohms

Next is Power

W=IxV
I=W/V
V=W/I

W= Watts, I = Amps, V = Volts

Lets look at a typical 21W tail light and how to swap that for a LED replacement which is something I have recently done.

21W at a typical 13.8V (engine running) will consume 21/ 13.8 = 1.52A

Next you need to measure the current draw by the replacement LED, don't go off the values printed on the packet you need to measure this, it will be much lower than the bulb you are replacing, mine were 0.27A for the rest of this example I will use these figures to try and explain how to work things out.

Subtract the LED amps value from the bulb value:

1.52 - 0.27 = 1.25

This is the amount of current you need to dump through the resistor.

Back to OHMS Law to calculate the ohmic value of the resistor needed to "waste" 1,25 amps when supplied with 13,8 Volts (typical car DC supply with the engine running)

R=V/I

R = 13.8 / 1,25

R = 11.04 Ohms

Any resistor value close to this will be OK to use as they only come in specific values but we only know the ohmic value required at this point, we now need to calculate the rating or Wattage of the resistor in order to get one capable of working without burning out:

W=IxV

The resistor is having to dump 1,25A running at 13,8V so

W=1,25x13,8

W = 17,25

Any Power resistor above this rating will suffice so we now know we need as close to 11 Ohms at 17W to achieve the equivilant to a 21W bulb, the ohm value must remain as close as possible to the target value but the wattage can be higher as that's just a rating of the resistors ability to dissipate heat.

For indicator lights you can save some cash by halving the wattage rating of the resistor due to the 50/50 duty cycle of the light, but to stay on the safe side fit 25W rated metal clad resistors screwed to the cars body work as this acts as a heat sink.
 
Don't think you know us that well

most of us are over weight - quite thick and read the sun news paper :D
 
Just looked at the last GS911 autoscan report of my bike (on a desktop file), the ZFE unit report says "Brake light switch over CAN" and "Rear Bulb Replacement" which suggests it knows the rear bulb is different eg LED type ??
 
I thought they were plug and play ? (otherwise I should have a recoding option on my GS 911 ??)

Yes they are, regardless of what the bmw dealer may tell you about reprogramming being needed ...
 


Back
Top Bottom