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View Full Version : Brake light (warning light)


smufguy
11-26-2002, 02:08 PM
Hey guys, i got a question for you all. I switched my third brake light to a bar led light as some of u know. But the annoying thing is, on the gauge, with the lil car pic, The brake (bulb blown off warning light) light comes on. NOt the one with the Ebrake 'brake' light, but the light that comes on if u blow a taillight. What might be wrong? Is there too much resistance in the LED compared to a Normal bulb? How do i fix this? I know many of u guys have dont a mod like this.
DBMaster
11-26-2002, 08:06 PM
Actually, it is because the LED has too LITTLE resistance. One of the other guys on this board said something in the past about putting a resistor in line to increase the resistance, but unfortunately I can't give you any more information than that.
smufguy
11-26-2002, 08:52 PM
hmmmm, if the line is open, as in the blub is blown, there is no conuctivity bwt the two prongs which leads to no currnet flowing bwt them. This in turn leads to infinite resistance. but on the other hand, if there is a very lil resistance, it would be just a short. Atleast thats what i learnt.

so with that concept in mind, i wonder what is wrong. Cause thats one of the reason u put a really bright bulb (high resistance) in place of a normal one, and u see the sensor go off.
DanG86LX
11-26-2002, 10:34 PM
"Is there too much resistance in the LED compared to a Normal bulb? "
Right on money man!
The resistor should be tied in parallel with the LED. But what value ? u should experiment a little, or maybe a smaller bulb will do...
smufguy
11-27-2002, 08:01 AM
i wonder how much ohms the resistor is. U know what, for the time being, i can run the stock 3rd light to it and have it running. :D
dosh8er
11-27-2002, 08:06 AM
dosh8er
11-27-2002, 08:07 AM
hrm.. just take a multimeter... go in where the taillight has its connectors (the original) and place the ohmmeter (measures resistance) across the unit.. that will give you an idea. (then you could measure the new leds for resilstance.. and find the difference)
smufguy
11-27-2002, 08:10 AM
ahhh ahah, u got what i was thinking. I was looking at the multimeter on my table and i was like, u kow what i would measure the resistance and subtract it from the led and get that. And here u are, u said the same thing. It might work right?
Midnight
11-27-2002, 08:42 AM
led light? how got any pics. I wonder how that looks?
smufguy
11-27-2002, 09:48 AM
i am not a bember yet, so i cant post pics, but lemme give u the link to what my led bar looks like that one of the members posted. i took it with a webcam so the quality is not that great.

http://www.3geez.com/showthread.php?s=&threadid=3628&highlight=Brake+light

as u know they did not post my pics, so if u want it i can email you and yeah the price is not 60 its just 30 shipped to your door. Got 3 in my pocession as of now.
DanG86LX
11-27-2002, 10:15 PM
About the resistance stuff... is not quite so cuz what u measure with ur multimeter is a cold resistance, things are different when a current is passing through. A LED is sort of a diode which means its resistance is function of current. Same with a bulb. I suggest u measure the current going through both LED and bulb @12V, take the difference say dI , divide 12V/dI = required resistor.
smufguy
11-28-2002, 08:26 AM
thanks Dan, me personally am not a electrical guy. i can wire shit like anyone else, but have no interest in that mechanics behind it. Thanks Dan, i will get it and let u know.