I am still on the quest to find a solution to why the multi-led citylight bulbs are failing on our cars.

I thought it might be a issue with current or voltage spikes to I sepnt most of today trying to find a solution.

I rigged up some static value resistors and 2 variable value potentiometers to I can put them into the headlight circuit in various series and parallel configurations to see what happens.

Series current limiting resistor:

The current rating for the UltraLED citylights is 20mA so assuming a median voltage of 14V a 680ohm current limiting resistor is required. I cut my citylight positive wire and tapped in a 680ohm 1W NTE resistor, inserted a new LED bulb and turned on my headlight switch.

The LED was solid then proceeded to blink.

I swapped out the 680ohm resistor with a variable value potentiometer and got the same result. The LED blinks. The more resistance I added the the bulb dimmeed but it would still blink.

So this solution doesn't work.

Series current limiting resistor with Load Equalizer:

So I hooked up the 680ohm current limiting resistor and 220ohm load equalizer to see what would happen. I was pretty sure this wouldn't work as the resistance values would need to be recalculated and I was right.

I then proceeded to hook up 2 variable resistance potentiometers to see if I could dial in the values required without sitting down and calculating the values needed. Well no such luck. Either the LED would blink or not light up at all.

So this solution doesn't work right now without some time to calculate what is going on with the resistance values.

I haven't had a chance to rig up a 12V voltage regulator in series with the LED yet to provide it with the exact amount of power it needs.

That will be the next test when I have time to solder it all together.

I am going to order these bulbs and see just how durable they last.

http://www.ultraleds.co.uk/product_i...oducts_id=1316

 

Hammered i looked at these as well, very pricey but mite be a good solution for u, i dont have the same prob a u though

I dont know why u have these issues, since u have the E-codes and u dont have the heat affecting the LEDs?

The new LEDs u mention are a tad fugly compared to the BAX9 in the 6 LED

 

So are you running the new LEDs??

I don't know why the 6 LED bulbs are failing but I have heard that single LED citylight users are not having the same problems as I and others are having.

 

Nar mine are all good, thats the 6 LED ones, and i dont really need the new ones with the metal upper housing

Good luck let us know how its goes

Hay Hammered, just refresh me memory, does the B6 have the bulb out warning signal for the City lights, the B5 doesnt, therefore no LE needed