**FIXED** new clear LED 3rd brake light, now no cruise?

Hi all, Just in case someone else has come across this issue: I've recently put a clear LED 3rd brake light in, after a few days I noticed the cruise control wasn't working (No green light on the dash when switched on and off). I put the OEM red original brake light back in and the cruise works fine. Put the clear LED one back in and no cruise control. Does anyone know if the LED 3rd brake light might need a ballast resistor (like the indicators do)? Thanks for any pointers, Ian

Probably. Do you have access to a multimeter (ohmeter) to compare the resistance of the clear vs OEM.

Ian, Do you minds me asking where you got the light from? i've been looking for one but wit no sucess. Sorry to go off topic :?: Thanks in advance,

Nuri, I got it from a bloke called Bash in Birmingham. Top bloke, highly recommended, a pleasure to deal with, give him a call on either 0121 773 3344 or his mobile 07830 223797 I think he had a couple left. It takes two minutes to fit and is a really bright red when it's on and perfectly clear when off. GT4, Thanks for the ohmeter tip, I'll give it a try. Cheers, Ian

Ian Take a look here: http://www.renntech.org/forums/inde...ed-tail-lights/page__view__findpost__p__68777

Thanks Richard, Good one. Seeing that thread made it dawn on me that I also have the LED replacement rear lights so it's probably lack of resistance. I've just ordered a 50W 12V resistor which should sort it. I'll report back on here when I fit it just in case someone else searches and finds this thread in the future. :thumb:

It's actually an over abundance of resistance! The system sees the effectively infinite resistance (tiny flow current at 12v) of the LEDs and thinks it has an open circuit (bulb blown/missing). You put the resistor in parallel (ironically to reduce the total resistance!). 50W @ 12V resistor = 2.88 ohms (probably 3R if 5% tolerance)

What a great photo. Looks the business. :thumb:

Interesting as when our car had a faulty brake light switch so the brake lights were permanently on the cruise stopped working.

Thanks Richard neil_c, The brake light switch is connected to the cruise. When you tap it and the switch operates it cancel the cruise. So when that switch is faulty it's like having the brake pedal pressed all of the time and the cruise is stopped. Seems to be a fairly common fault on boxters and 996's. In my case the switch is ok. ****UPDATE**** Thanks for all of the replies. The 50W resistor, neatly fitted and soldered into the wiring (plenty of room inside the area where the 3rd light goes) (about £3 off ebay) has fixed it.

Thanks for the details Ian, I also have the led rear lights so expect this problem also. Could you post some pics of the resistor you had to install and some commentary around what you did before I order the light? Thanks in advance for your help Nuri

Nuri, I bought one of these http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310093684649 because I have a soldering iron etc etc I put the wires and insulated them myself, however, if you haven't got a soldering iron then the same seller sells the 50W resistor with wires attached and also scotchlocks as a kit, take a look at his 'other items'. The resistor arrived quickly in the post. It's a very simple fit, loads of room when you take the 3rd brake light to put the resistor at the side of it. I used some double sided sticky tape under the resistor to stop it moving around. Just pull the LED light out, plenty of wire, attach the resistor across the wires. If you have any questions at all give me a shout on here. Best wishes, Ian