# MkIV - LED turn signals in taillights: where do I splice a resistor??



## kounterkultured (Apr 9, 2006)

OK so I want to use LEDs as my turn signals in the back of my GTI.
Noobishly enough, I figured they were just plug-n-play so when I installed them LEDs in, I got hyperflashing







. Since then, I've learnt that they do not draw enough current and the hazard-switch believes one of them is burnt, hence the rapid blinking.








I can not replace the flasher relay on a MkIV (it's built in the hazard switch) and yes I've found this DIY http://homepage.ntlworld.com/d...s.htm but I do not want to do that; it's clever and all but I'm not all that good with a soldering iron...








Next solution; I want to buy a load resistor kit like the ones from superbrightleds http://www.superbrightleds.com....html My issue is: does anybody know where to correctly splice it in in the tailight harness?? Or could someone be kind enough to provide me with a MkIV taillight wiring harness diagram? 
http://****************.com/smile/emthup.gif Thanks in advance http://****************.com/smile/emthup.gif


----------



## .:RyouExperienced (Sep 19, 2005)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*

I am having a similar problem (except with the front turn signals). You need to place the resistor in-line with each bulb. This can be done at the wiring right before the bulb itself since the previous bulb is what provided the appropriate resistance. The real question is what resistor is needed to achieve this? All you really need is two small resistors from radioshack and some electrical tape and you should be fine. Anyways, not to hijack but anyone know the specs of the 3457 and b5 Passat position lamps/overhead side map lights?
I found this post useful. Especially when redmondjp chimed in.
http://forums.vwvortex.com/zerothread?id=2375533


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (.:RyouExperienced)*

That is excellent info indeed, thanks! http://****************.com/smile/emthup.gif 
My issue remains, though: what wire in the tailight harness of a GTI is the flasher (and which one is the ground)?? 
IDK... it may be obvious to somebody but I'm more the mechanical type


----------



## EternalMind (Jun 8, 2005)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (.:RyouExperienced)*

there is a bit more to it than this. it doesn't really go "in-line" (which alludes to being in series); it would actually go in parallel. also, not only the resistance value needs to be chosen correctly, but also the power rating of the resistor. this is where more of the challenge comes in. to dissipate the amount of power needed, it has to be a (relatively) large resistor (typically 5W or greater)...not the small kind at radio shack (which are typically 1/4W). 
this is a very inefficient way of doing this as the resistor is basically just disippating all the power through heat. it works, but maybe isn't the best idea. changing the flasher is a better way to do it.


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (EternalMind)*


_Quote, originally posted by *EternalMind* »_there is a bit more to it than this. it doesn't really go "in-line" (which alludes to being in series); it would actually go in parallel. 

Yes, of course a resistor needs to be spliced in parallel. Im sorry I may not have been very clear as to how I would splice it in. 

_Quote, originally posted by *EternalMind* »_also, not only the resistance value needs to be chosen correctly, but also the power rating of the resistor. this is where more of the challenge comes in. to dissipate the amount of power needed, it has to be a (relatively) large resistor (typically 5W or greater)...not the small kind at radio shack (which are typically 1/4W). 
this is a very inefficient way of doing this as the resistor is basically just disippating all the power through heat. it works, but maybe isn't the best idea. 

I chose to get a 6ohm-50watts resistor load kit straight from where I got the LEDs ( http://www.superbrightleds.com ). I assume from previous searches on the subject that it'll be OK... or any Dale DH-50 resistor gotten on eBay wouldve been allright. I also know it's not the best idea, and that...

_Quote, originally posted by *EternalMind* »_changing the flasher is a better way to do it.

...but is there any possible way to do that on a MkIV, when the flasher is integrated in the hazard switch??







If that was the case I'd do it; I thought it was impossible because its not like an older model where I could have just swapped the relay and voilà!!


----------



## .:RyouExperienced (Sep 19, 2005)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*

So I found a great site for finding out specific information about bulbs here.
http://www.donsbulbs.com/cgi-bin/r/t.pl
...then after doing those physics equations lol, I found out I needed a 6.5-ohm 25 watt resistor. So I went to radioshack and picked up an 8-ohm 20w resistor, wired that baby up in parallel (sorry for the earlier confusion, it is in fact parallel), and lo and behold, success!
Turns out that you can fudge the voltage and resistance a bit and still have the thing work fine. http://****************.com/smile/emthup.gif


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*


_Quote, originally posted by *kounterkultured* »_I chose to get a 6ohm-50watts resistor load kit straight from where I got the LEDs ( http://www.superbrightleds.com ). 

Load resistor kits ordered!! More to come soon. http://****************.com/smile/emthup.gif 
I guess I can use a multimeter to see what wire I should splice but... I tried my luck to see if anyone had that information already.


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*

Damn!!







they have cancelled my order, they require a minimum order of 25$ for across-the-border shipments.
To hell with them, I have bought 2 Vishay-Dale RH-50 5 Ohm, 50 Watts resistors from [email protected]


----------



## A2Carat (Jan 13, 2003)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*

you don't need resistors. Just use an electronic flasher. I put led's all around on my car and used the electronic flasher. Now they blink perfectly.


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (A2Carat)*

Yeah, but you have a MkII, not a MkIV. Our flasher relay is integrated in the hazard switch so it's not all that simple.


----------



## A2Carat (Jan 13, 2003)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (kounterkultured)*

Ah .. ok.
Then this might help with your wiring ..
Does it look like this? (the pin out on your hazard/indicator)








If not .. try this


----------



## .:RyouExperienced (Sep 19, 2005)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (A2Carat)*


_Quote, originally posted by *A2Carat* »_
If not .. try this









...all you need to do. Took me all but 5 min.


----------



## kounterkultured (Apr 9, 2006)

*Re: MkIV - LED turn signals in taillights: where do I splice a resistor?? (.:RyouExperienced)*

Thanks loads!!

SUBJECT: CLOSED


----------

