I remember reading in the forum that the fitting of LED brake light globes might adversely influence the operation of the ABS unit in TJs and TLs...is this correct?

I know it can affect the cruise control.

I have installed LED's and resistors in my KL brake lights and its been fine. I did try first without the resistors and the cruise control would not work, as peandham mentioned.

I'd be intesrested to know if anyone has encountered issues with the ABS and what they were?

Stroppy: yes.
I have written a bit of a technical explanation somewhere on the site about this.
I think KWAWD has actually done it and confirmed what has to be done. I seem to remember one of his earlier, but recent posts on the matter. The question seems to continually come up, so maybe a guide somewhere may be a good move but I'm not sure where to put it.

I have installed LED's and resistors in my KL brake lights and its been fine. I did try first without the resistors and the cruise control would not work, as peandham mentioned.

What value resistors did you install and do you have a link to the LED's you used? Thanks

I just purchased a unpainted never fitted rear wing with a LED brakelight for my young blokes 98 Verada. Am i going to have trouble with cruise etc once fitted ?. Thanks.

I just purchased a unpainted never fitted rear wing with a LED brakelight for my young blokes 98 Verada. Am i going to have trouble with cruise etc once fitted ?. Thanks.

If you use the power lead going to the LED high mount stop light in the rear windscreen then I can't see a problem. I think the law says that you have to disconnect the high-mount windscreen light when fitting a rear spoiler with the stop light built in anyway.

Thank you stroppy, Should have it painted and fitted in the next few weeks and will try that. I will report back on how it went .

Have a good weekend.

Cheers

What value resistors did you install and do you have a link to the LED's you used? Thanks
Sorry didnt see this earlier. Cant remember right now but will get as much info as i can and post later.

try this link.
http://www.aussiemagna.com/forums/showthread.php?t=101101&p=1582645&viewfull=1#post1582645

I used these (http://aerpro.com/ba15d45r) and these (http://aerpro.com/ledres).
(Resistors are much larger than their photo suggests).

http://i1159.photobucket.com/albums/p629/Kwawd/618db1d2-86ad-4516-8d1c-9cfcdd4decd7_zps0e37123a.jpg (http://s1159.photobucket.com/user/Kwawd/media/618db1d2-86ad-4516-8d1c-9cfcdd4decd7_zps0e37123a.jpg.html)

According to the link, each resistor is 11 ohm. At 14.4 volt, these resistors will dissipate nearly 19 watts each. Thats why they are so big and get so hot.
A higher value of around 100 ohm will still hold the voltage level on the lamp circuit to less than 0.5 volt and will dissipate only 2 watt.
A 100 ohm resistor in each lamp position would be just fine.

According to the link, each resistor is 11 ohm. At 14.4 volt, these resistors will dissipate nearly 19 watts each. Thats why they are so big and get so hot.
A higher value of around 100 ohm will still hold the voltage level on the lamp circuit to less than 0.5 volt and will dissipate only 2 watt.
A 100 ohm resistor in each lamp position would be just fine.
Yes, I believe the 11 ohm resistors help to ensure similar current across the circuit and wattage as with the standard bulbs.
Why do we need to hold 0.5 volt or less across the circuit?

Thanks to all posters who replied here. I think I will stick with the normal bulbs. Less hassle. I'll just make sure I hoard a stock of them in case they stop being made. :)

For KWAWD,
The electonics detect whether the brake lights are ON or OFF by sensing the voltage across the stop lamp bulbs. To sense the voltage, the electronics actually send a very small current into the lamp circuit. With the normal lamp bulb, its cold resistance is so low that the voltage developed across the bulb is VERY small (less than 5 millivolt). With the LED, this type of device is effectively open circuit at voltages less than 1.5 volt so it is possible for the electronic signal to cause a LED lamp voltage of more than say 1 volt across the LED. The electronic sensors will be guaranteed by design to detect the lamp is OFF 'IF' the lamp voltage is less than say 0.5 volt. The electronics is not perfect, and there will be some level of lamp voltage (less than 12 volt) at which the electronics will say that the brakes have been applied because the lamp voltage will be above the detection threshold.
The electronics will define the voltage levels:
- LESS than 0.4 volt, the lamp will be OFF
- MORE than 5 Volt (say) the lamp will be ON
- BUT between these levels the electronics cant decide whether the lamp is ON or OFF, so it is critical that the circuit design GUARANTEES these voltage levels.
By changing from filament lamps to LED lamps, we are effectively redesigning the electronics system.
With the 11 ohm resistors you are right; but we only need to GUARANTEE the lamp voltage be less than the system design figure and this will be around 0.5 volt (maybe up to 1 Volt)
In the Magna manual you will see the voltage measurements given. (cant locate it right now but I have seen it). If you have a digital voltmeter, you can take the bulb out of the boot light and check the voltage on the lamp socket when the boot lid is shut. Similarly, you can connect a milliamp meter in series with the lamp bulb and measure the current in the bulb with the boot lid shut. You will find this current to be less than 20 milliamp. This is what happens in my TW

Hope this helps.

Thank you for that infomation rumpfy. Based on that analysis the only issue with the 11 ohm resistors is the heat dissipation, as all the other system requirements are met. I dont believe the additional heat will be an issue (assuming the resisters are well made). I do have a concern about them contacting anything that may melt or ignite (!) but it just means that they need to be carefully mounted on installation.

Operationally they're very good, bright, but not in that cheap LED hot-spot kinda look that you sometimes see, or wrong colour temp. These look very good and "factory" imo.