LED Day Running Lights

[PAH]

Thanks for your reply!

I tried to get the correct resistors from RS, but unfortunately they had none of the resistors for the DRLs and only one or the resistors for the sidelights in stock. I would have preferred to get exactly the same as yours, as I know they work (having read your reports), but RS didn't know when they would be back in stock, and said it would be AT LEAST September. I didn't really want to wait that long!

I am a bit concerned about the lower resistance resistor getting hot...so maybe I'll use the same rating ones for both the DRLs and the sidelights. Again, it is a lower resistance, but a higher wattage rating, so hopefully will dissipate heat better. I think I'll give them a try and see how hot they get before mounting them in the cap like you did. Certainly looks very neat though.

Please could you let me know which sidelight LEDs you used? The ones I bought don't fit, so I need to order some others!

Thanks again

Paul

[PAH]

Well, the LED's finally arrived from the States, so I tried the install last night.As I could not get the exact resistors I wanted for the sidelights, I went with 50W 24R for the DRLs and another set of 50W 24R for the sidelights.

However, I am still getting the "bulb out" warning for the DRLs (tells me that the left and right main beam bulbs are not working. As the DRLs are where the main beam headlights are on the non-xenon A4, I guess this is why it is telling me the main beam is out as opposed to the DRL.

The sidelights are fine - the 50W 24R resistor stops the pulsing of the LED, and supresses the bulb-out warning.

I've tried only one side at the moment, but no reason why fitting both sides would make any difference. The warning comes on straight away, and stays on no matter what I do (pressing check, turning lights on and off again etc). I think I need to get a different resistor, but lowering the resistance may generate too much heat, so I really don't know what to do.

At the moment I haveremoved the resistors, and reverted back to standard side lights. However I left the LED DRLs in place, putting up with the bulb-out warning because the lights look so good! Really pleased with the 60 LED SMT bulbs, as they are extremely bright, and complement the xenons perfectly. I just wish I could get rid of this bulb-out indicator.

Any ideas?

[Andyuk911]

The Resistor is wrong ...mine work fine .. search Tyresmoke for my write up

[RJKflyer]

Do i understand correctly that you get BOTH bulb warnings even though you've only done one side for the DRLs?

Aside that, I'm 100% OK with those value resistors. The only think i can suggest is that either the US cars have a slightly different 'sensitivity' or i was lucky. Irritating though i appreciate it is, try 20R - you'll be still OK with dissipation etc. You could try 22R but i'm reluctant to suggest that and waste your time, although the highest you can get away with the better.

Agree though that the 60SMT are stunning!

[RJKflyer]

Andy - I don't think you can say mine are 'wrong' - i tested values until i could consistently get the bulb warning to stay off as opposed to just choosing ones that would be 'equivalent' to the bulb in order to reduce heat dissipation.

The obvious risk in this is that the precise sensitivity of the warning system may vary and so it is possible that not everyone will be successful with exactly my values.

[craigyb]

The problem is that a 22R resistor will only draw laess than half the current of the 10R resistor so there is less load on the circuit and thats why the system probably thinks the lamp is out. Try putting two 22R resistors in parallel and that would make 11R and test it on one side. See if the warning lamp goes out for that side, that would prove that you need a lower value resistor.

[PAH]

Thanks guys, I really appreciate your advice and feedback on this.

RJK Flyer - yes, I only did the passenger (left) side of my car, but both bulb warnings (left and right) came on. I was expecting the right to come on as there was the SMT bulb, but no resistor. However, the left one also came on. Interestingly, with the 50W 24R resistor, the parking light (sidelight) warning went out. I have wired them exactly the same as yours.

As I bought 4 of the 50W 24R (one each for the DRL (left & right) and sidelights (left a& right)) and 2 of the 25W 47R resistors (effectively spare), would it be OK for me to connect the spare 25W 47Rs in series with the existing 50W 24R resistors on the DRLs? Would this increase the resistance, and perhaps surpress the bulb warning?

Otherwise, I'll just go with another 50W resistor with a slightly lower resitance.

I wish I knew a bit more about electronics!!!

Thanks again for all your help.

Paul

[craigyb]

Putting the resistors in series will increase the resistance and lower the current draw even more. So I doubt if things will change.

With Andy's 10R resistors he seems to have the correct balance of current draw/detection to say the lamps are standard.

[PAH]

OK, Andy's resistors were 10R, but were they 50w do we know, or a different rating?

I'm going to order a few resistors, some 10R ones like Andy's, and also some 20R 50w to see if they work...hopefully I'll get a solution!

Craig - sorry about that - of course the series orientation would increase resistance - I meant to say parallel...!!

[GotRS?]

Originally Posted by PAH

3) DON'T buy the LED sidelights that I got, as they don't fit through the aperture in the existing light unit. I need to order some different ones.

What did you get in the end, or did you just shave those ones down a bit?