Strange R33 Electrical Problem After Led Tail Light Install

[Granthem]

Hi guys,

Got sick of my standard rear bulbs causing blinding, hideous pink brake and tail lights.

So the answer, 36 bulb LED rear tail lights like shown below (left is LED, right is standard)

Now, the problem is, when driving, applying the brakes causes:

1. the clock to 'dim' as if you have turned the parkers on at night (a standard R33 function I believe)

2. the a/c panel to dim (as above)

3. my dvd player to dim (as its wired to when my parkers turn on also)

4. my 3 GReddy gauges to light up (dull, but none the less, they get power to the light in the gauge)

When i let off the brake pedal, everything goes bright again (except my gauges, which cease to light up)

I am fairly stumped as to why a simple tail light bulb change could start messing with this stuff. Its on a totally different circuit, I would have thought?

If I have my parkers on, and everything dims as normal, then applying the brakes does not make anything dim any further.

All I can think is that the "dim" is operated by currents being drawn by the lighting system in total? And lighting up all the LEDs (144 + gtr wing LEDs) is causing the car to think I have put the parkers on? Although this seems stupid, its the only explanation I can gather. ( I am aware LEDS draw very low wattage. The bulbs are 5W I think)

Or has a short somehow magically appeared? I am confused to say the least. Any help would be great.

Edited July 11, 2010 by Granthem

[RANDY]

hmmmm..... it sounds like the globe is telling the car that the headlights/taillights are on. (as you say with the dash-dimming)

Perhaps check that the LED globes have the same contacts... because the tail lights are all high/low (unless compliancing fiddled with the wires), each globe socket should have TWO metal contacts, and the globes will have two seperate contacts also.

I would think, if your LED's have ONE contact, it would be bridging the two contacts in the socket... .so when the brakes are on (brightly), it is feeding power to the LOW contact, so the electrical system thinks your normal lights are on, therefore dimming your display.

I would think that your parkers would come on at the same time, and your instrument cluster?

In any case, check the contacts of the LED's and sockets. =-]

Let us know!

[tridentt150v]

I'll see if I can find it, but I read somewhere that the LED's are a different impedance and you have to use them with some sort of adaptor otherwise all your lights go haywire............damn I can't remember which www or forum I read that now.

Edit: had a 10 minute look - there is some random stuff on the web about resistor boxes and having to calculate the resistance you will need etc but I can't find the article I was looking at. If I do I'll get back to you.

[89CAL]

might have something to do with the bulb being 2 stage instead of having 2 filaments for lights/brakes

perhaps when u stand on the brakes its sending the power up to the light as its supposed to but then letting power trickle through your headlight circuit giving the items wired into the headlight dim circuit

so not causing a full voltage through the circuit but a small circuit

just a theory

If that is the case but it may be a faulty LED globe

Edited July 20, 2010 by 89CAL

[RANDY]

might have something to do with the bulb being 2 stage instead of having 2 filaments for lights/brakes

perhaps when u stand on the brakes its sending the power up to the light as its supposed to but then letting power trickle through your headlight circuit giving the items wired into the headlight dim circuit

so not causing a full voltage through the circuit but a small circuit

just a theory

If that is the case but it may be a faulty LED globe

Sounds a lot like my theory! =-p

[89CAL]

Haha sorry

I read your post a bit to quickly the first time.....

I have basically just re-wrote your description

lol but yeh it may just be a faulty bulb, change back to a standard dual filament brake light and see if the problem is still there

if it is, try a different LED brakelight

I bought one ages ago from dick smith that im pretty sure worked fine in the skyline, I just didnt bother to keep it in there

[SixShooter]

Sorry to wake up an old thread.

I've also changed the bulbs with LED's and had the same problem. Couldn't find anything on the web so decided to find my own way. Anyway...

SOLUTION:

When you hit the brakes, LED bulbs cause more feedback (more voltage) to the rear parkers than filament bulbs. Basically, three cables connecting to your taillights (except for reverse and indicator lights). One for braking, one for parkers and one for earth.

If you put a "6A diode" (you can buy from Jaycar around $2) to the cables coming for parkers, it solves the problem.

Cheers,