Help with LED brake lights

[WildPuppy]

Re: Help with LED brake lights

Not exactly identical to your problem, but still similar...

https://www.youtube.com/watch?v=tci97uxfptA

OffTopic: Happy Easter

[WildPuppy]

Re: Help with LED brake lights

Wouldn't this work if your schematic were correct?
I am sure you have some relays there in the car, nothing is wired directly to the consumer...



Depending on the power those LED's and whatever else is inside that bulb draw, it may have to be a strong diode...

[Dannyx]

Re: Help with LED brake lights

Wouldn't this work if your schematic were correct?
I am sure you have some relays there in the car, nothing is wired directly to the consumer...



Depending on the power those LED's and whatever else is inside that bulb draw, it may have to be a strong diode...

That is what I tried and it only solves half the issue: the LED lamp no longer turns off when the brake is up (grounded), but it doesn't change intensities either when the brake IS depressed.

[WildPuppy]

Re: Help with LED brake lights

Try one diode per each circuit. Other than that, get some more expensive but properly built LED replacements

[Dannyx]

Re: Help with LED brake lights

I shall. I'm also thinking the LED bulb doesn't like being in parallel with a regular filament one...I shall experiment on the bench first though - much easier, though it could yield inconclusive results as we just saw: I wasn't thorough enough in my original diode test, I saw it working on the bench and thought there's be no way it wouldn't work on the real thing, so I just rolled with it only to run into the aforementioned issue....

[petehall347]

Re: Help with LED brake lights

wire a standard bulb in parallel next to each led . i know it sort of defeats the object but will get the job done . its that or large resistors in parallel . had to wire in bulbs on a motorbike indicators . also had to fit diodes in the speedo head .
does the car have bulb out warning light on dash ?

[Dannyx]

Re: Help with LED brake lights

I was planning on doing just that.

[Dannyx]

Re: Help with LED brake lights

Ok guys, back on this project, since I didn't have much time. I set up the...setup on the bench trying to replicate the one in the car as closely as possible: regular dual filament bulb in parallel with LED lamp with diode. I connected both filaments in the dual filament bulb to + straight off the adapter to simulate both the parker and the brake being pressed (no diode in between) then connected the parker terminal of the LED bulb to the adapter directly (no diode here either) then the brake terminal through the diode as well and it works: the LED lamp becomes brighter when I touch the cathode of the diode to the brake terminal...great....so why the hell isn't it working in the car ? It's extremely annoying...

[WildPuppy]

Re: Help with LED brake lights

It may be that your car is not as old as you let us believe and it has light bulb checks integrated in the logic. In this case, when it "senses" that the filament is not there, it may cut the power going to that bulb (or line of bulbs) or at least show an alarm light on the dash board.
In this case, an filament equivalent resistor should be added in parallel to each LED branch to tell the on-board computer that the light bulbs are OK.

Just my two cents... I am by no means a specialist, more like an heavy car user.

PS: maybe this may help ? I admit I didn't read it all...

[Dannyx]

Re: Help with LED brake lights

No it's definitely not "old" - got it new in 2007...some may even be familiar with the model: it's the world famous Dacia Logan Anyway. I'll have a scrub though the wiring diagram - you may be right. There may indeed be some electronics involved and the two rear lights are not paralleled after all, so the functionality of one doesn't guarantee the other one works as well...

I have seen others do this sort of mod and it worked without any issues, though the bulbs weren't identical - I reckon they had two individual separate "stings" of LEDs for high and low brightness...

[Dannyx]

Re: Help with LED brake lights

Here's the wiring diagram for this particular car (may have to use google translate or ask me personally if you really want to dig into it).

Have a look on page 65 which shows the braking circuit, with box 160 on the left side being the pedal switch...there doesn't seem to be any additional circuitry there - just toggles between GND and VCC, HOWEVER notice box 118 below it, which according to the legend is the ABS control unit, that is, when you press the pedal, VCC also goes to it, which makes sense: the ABS unit needs to know when the bloody pedal is pushed in...don't know how or IF it affects our issue with the LED lights...

[petehall347]

Re: Help with LED brake lights

you may need a relay for led lights . if it uses relays that is
yes i just read your post . lamps need to be drawing current or it throws faults .

[Dannyx]

Re: Help with LED brake lights

yes i just read your post . lamps need to be drawing current or it throws faults .

You sure about this ? How can you tell ? I know for sure this is valid for the turn signals - if a bulb burns out or is removed, the ECU beeps/blinks faster and I tried it myself - but not sure it applies to the brake lights too...

[WildPuppy]

Re: Help with LED brake lights

... (may have to use google translate or ask me personally if you really want to dig into it)....

Hehehe you're funny, you're not very keen on details, are you? I'm from the same shithole known as RO.

Ok, joke aside, I know you said that for all the other members.
I have to agree with petehall347 here and think you need a special relay for LEDs since in the schematic it is not very clear how the relay or the brake pedal contact works internally. Let's say it is more like a block diagram (quite usual in auto industry) than a true schematic.
Did you try the specialized local forums like DaciaClub and Duster? They are quite large forums with a lot of helpful members.

[sanjurahul]

Help need Panasonic bios

guys please Panasonic CF-53 schematics and bios

[Dannyx]

Re: Help need Panasonic bios

Wrong thread I'm afraid

[Dannyx]

Re: Help with LED brake lights

Hehehe you're funny, you're not very keen on details, are you? I'm from the same shithole known as RO.
Ok, joke aside, I know you said that for all the other members.

Bingo

No, I haven't turned to any local forums yet....I try to avoid them as much as possible since they're not particularly friendly. Everybody thinks they're pros and tend to treat you like sh!t....anyway. Not to impugn on any people out there who actually ARE trying to help.

I took a peek under the dash long ago to have a look at that brake switch and it's just like a regular button. I even replaced one on a buddy's car...internally, I don't think it's that special. I had another closer look at the schematic and it turns out the switch isn't actually grounding the brake lights when not pressed (notice how there's no ground wire leading into it) - it just lets them float, but the filaments act as resistors to GND, so that's why when I put my black probe on the brake terminal and the positive probe to a 12v-enabled terminal, I got a reading: the meter was grounding through the filaments, especially since there's 3 bulbs in parallel (there's 3 brake bulbs - the third one being in the middle of the rear window) and the resistance drops even further as opposed to my single bulb setup on the bench. This might explain why the LED bulbs don't come on when installed on their own, but still doesn't explain why the brightness doesn't change even with that diode in series...something's demonic about that car

[WildPuppy]

Re: Help with LED brake lights

Just had a look online for the brake pedal contact and it seems to be a simple 2 wire on/off contact, so we can take that out of our problem here if I found the correct switch.
You're right, going back to your 12V measurement on the contact, it may have mislead you because of the connection to ABS that may have pull down resistors and the existing bulbs in the sockets that also lead to GND.
So, after all the talks here, there would no reason for the LED's to not work. But still, they don't...
Did you try to reverse the two +12V signals coming to the LED's in the car light housing (pins 3 and 4)? Maybe the two are reversed inside the LED enclosure and that can cause some miss-behavior.

[Dannyx]

Re: Help with LED brake lights

I can't remember...I tried a bunch of things, both on the bench and the car, so it's hard to keep track I can't remember if the bulb came on bright or dim with the diode setup on the car - the one where it DID come on but didn't change brightness. So what you're saying is if the wires were reversed, then the parker wire was going to the brake terminal of the bulb and was already keeping it at full brightness, explaining why touching the other terminal to 12v made no difference.

[Longbow]

Re: Help with LED brake lights

Sorry if I find this very funny. I've never had any problems like this, but it is very interesting. I'd like to know the brand or the web site that provided the LED unit. I've always had good luck with Superbrightleds. You might be surprised at what they can stuff into an LED module that may interfere with your project.

I think this vehicle has a lamp-out feature. On most vehicles it just illuminates a light on the dash, but some vehicles cut the power to the light. The most critical circuit has always been the directional flashers which never work unless you also replace the flasher relay with an LED style relay.

You will always see ballast resistors sold with automotive LED's because of this problem. Obviously it doesn't make sense to use an LED, but then place a resistor in parallel with it to draw enough current to satisfy the lamp-out circuit, but that's what is necessary to do the replacement.

Finally, it is incorrect to measure the lamp socket using a high impedance multimeter. Use an automotive test probe with an incandescent lamp in it. This way you will not get a phantom reading. Also, parallel your LED unit with a power resistor (2 needed in your case) of correct value to match the load of the original lamp. I think you will find it will work.