Interesting LED sidelight problem...

[Batesyboy]

Hi,

New to forum, just acquired 2003 Z4 3.0i SE Roadster and my first mod has been to fit LED sidelights that I had in my old Clio - they're the ultrabright ones already mentioned on here, that look yellow on the front face.

With the new LEDs in place, and sidelights turned ON, the indicator bulbs come on (dim). When I turn on main beam (Xenons) they go out again and similarly on AUTO all seems well.

But when I turn the ignition off or lights to OFF, the LEDs stay on (dim).

Anyone know why..?! Admittedly they were from my Clio (bought from eBay) so I may need some with a different resistor that's more Z4 friendly...

Obviously I'll need an answer sharpish or it'll drain the battery - so I'll have to swap to the filament bulbs tonight..!

Cheers
- Andy

 

[Batesyboy]

Ah, found this thread on here: http://www.z4-forum.com/forum/viewtopic.php?f=2&t=2392&p=38143&hilit=LED+sidelight#p38143

Can anybody explain to me the resistor mod - I'm a little unclear on the diagram..! Mine are the Superlux LEDs like those on there as used by cj10jeeper...

Thanks
- Andy

 

[Smokin]

I would drop a pm to cj10jeeper. He definitely knows more about that mod than most on here.

 

[Batesyboy]

Even more interesting is the LEDs go out after approximately 1 minute... I just went back out to swap the originals back in and noticed they had gone out so I unlocked the car (they came on again dimly) and relocked it... and timed it - one minute then they went off again.

Could this mean they're OK..? :?

Or is this merely a "one minute" parking light feature I wasn't aware of or even noticed before..?!

 

[hotdog3147]

LED's by design will hold a slighty charge which is why they stay on when the circuit is broken (i.e. lights switched off) the circuit is not live so it won't run the battery down, so don't worry about that.

Or

the other reason is that as LED's don't need or use as much power, the ciruit will always have a slight charge running through it (testing the circuit for breaks, i.e. when the bulb does go) this small amount of power will not be enough to light a filament bulb but enough to light a LED. The slight power will be for the computer to check the bulb is fine, so as the warn you when the bulb fails (dashboard light).

 

[cj10jeeper]

Oh - can't even remember this one - more than a year since they were fitted and long since disconnected and replaced with CCFL Angel Eyes leaving the sidelights just as dummy bulbs.

That said when you drop an LED into the circuit you need to add a ceramic resistor to get the current drawn up to 5w (the amount that a standard side bulb takes) Without the resistors you get anything from bulb out on the dashboard to indicators staying on static.

Opinion - ditch the old LEDs and start again with either a pair with built in resistors, or a new pair and matching resistors, wired in parallel inside the back of the headlight unit somewhere that the heat generated will not touch any plastics or wire

 

[pungo]

LED's by design will hold a slighty charge which is why they stay on when the circuit is broken (i.e. lights switched off) the circuit is not live so it won't run the battery down, so don't worry about that.

Ummm, LEDs don't hold a charge, they actually turn on and off substantially faster than a incandescent bulb.

 

[Batesyboy]

Well whatever, the bulb warning indicator is on in the dash so it needs sorting one way or another..!

I *really* like how bright and white the LEDs are so I do want to persue it; I'm going to measure the resistance of an original filament and solder a resistor to make up the LED to the same in line with the loom.

I have seen some load balance resistors that you can Scotchlock on but not sure I fancy that much of a bodge job...

Will post some pics when I get it sorted.

- Andy

 

[cj10jeeper]

Well whatever, the bulb warning indicator is on in the dash so it needs sorting one way or another..!

I *really* like how bright and white the LEDs are so I do want to persue it; I'm going to measure the resistance of an original filament and solder a resistor to make up the LED to the same in line with the loom.

I have seen some load balance resistors that you can Scotchlock on but not sure I fancy that much of a bodge job...

Will post some pics when I get it sorted.

- Andy

All you need is something like this:
http://cgi.ebay.co.uk/2x-25w-LOAD-R...3286.c0.m14&_trkparms=66:2|65:1|39:1|240:1318

I would call them to see if they do a lower wattage, esle just pick some up from Maplins, etc.

Just needs neatly soldering in parallel and shrink wrapping inside the rear of the headlight unit. IIRC grey is live to the sidelight and brown in earth.