Newbie Posted May 16, 2006 Report Share Posted May 16, 2006 My 96 850 keep giving me "bulb" warning because I bought the LED light bulb. My question is..... I think I need a resister to make my car think my stop-light bulb is working.(LED use ultra low voltage)I was thinking, buy a resister off Radioshack and solder it, but I have no idea which one I should get...Help? Link to comment Share on other sites More sharing options...
Che'_Moderator Posted May 16, 2006 Report Share Posted May 16, 2006 My 96 850 keep giving me "bulb" warning because I bought the LED light bulb. My question is..... I think I need a resister to make my car think my stop-light bulb is working.(LED use ultra low voltage)I was thinking, buy a resister off Radioshack and solder it, but I have no idea which one I should get...Help?How many leds in the cluster?Generally a 2 ohm resistor will do fine for brake or back up bulbs, Link to comment Share on other sites More sharing options...
BeachRat Posted May 16, 2006 Report Share Posted May 16, 2006 Where did the LED go? Most bulb LED sets come with sufficient internal resistance to compensate for that... apparantly yours did not. Radio Shack or Fry's Electronics will have inline resistors that you can solder to the bulb, I don't know what ohmage though. Chuck's idea of 2ohms sounds about right though. Link to comment Share on other sites More sharing options...
The Poi Posted May 16, 2006 Report Share Posted May 16, 2006 the problem is that the LEDs have pretty high resistance to work with 12v, as they draw milivolts. there's no way to wire in resistors to lower the resistance the bulb sensor sees... Link to comment Share on other sites More sharing options...
Che'_Moderator Posted May 16, 2006 Report Share Posted May 16, 2006 the problem is that the LEDs have pretty high resistance to work with 12v, as they draw milivolts. there's no way to wire in resistors to lower the resistance the bulb sensor sees... :huh: Link to comment Share on other sites More sharing options...
The Poi Posted May 16, 2006 Report Share Posted May 16, 2006 dude you don't know much Link to comment Share on other sites More sharing options...
prasamin Posted May 16, 2006 Report Share Posted May 16, 2006 dude you don't know muchis your car good to go yet? i want to see it man! Link to comment Share on other sites More sharing options...
Che'_Moderator Posted May 16, 2006 Report Share Posted May 16, 2006 dude you don't know muchDude! Load balancing LEDs is not hard to do. May take a few tries, but 10 packs of LEDs are cheap as are low tolerance resistors. Link to comment Share on other sites More sharing options...
JHEIII874T5M Posted May 16, 2006 Report Share Posted May 16, 2006 is your car good to go yet? i want to see it man!Pras, relax, you know 960Rs take a while to develop. Link to comment Share on other sites More sharing options...
BeachRat Posted May 16, 2006 Report Share Posted May 16, 2006 the problem is that the LEDs have pretty high resistance to work with 12v, as they draw milivolts. there's no way to wire in resistors to lower the resistance the bulb sensor sees...Duuude, I've done it. It's a lot of trial and error, but it's possible. Most LED's require about 3V to run, and with a 12V source you can get away with 3-4 in series. You're still fretting the bulb sensor, so I'll imagine your poking with the headlights/tailights. Again, did you buy pre-made bulbs or are you splicing in raw LED's?Dude! Load balancing LEDs is not hard to do. May take a few tries, but 10 packs of LEDs are cheap as are low tolerance resistors.I bout a pack of 100 w/ resistors for $16 on ebay, I'm sure you could find the same deal, if not a better one. You can tell when they're fried, just do trial and error until you get it.Ultimately you could just pull out the bulb that lights up the "Bulb" indicator. Link to comment Share on other sites More sharing options...
Newbie Posted May 17, 2006 Author Report Share Posted May 17, 2006 How many leds in the cluster?Generally a 2 ohm resistor will do fine for brake or back up bulbs,sorry, been a long day.I have the 6-led bulb (sorry guys, this is NOT those fancy in-line modification, just a regular looking bulb that are made of 6 LED)And I am seriously no clue what-so-ever which resistor I have to pick up at Radioshack.I see their online catalog and there is 1/4watt w/ ohm? and 10 watt w/ xxx ohm....I just want a simple resistor that I put them directly from positive end to negative end (NOT attaching the bulb, but just solder into the bulb socket)REALLY DRIVE ME CRAZY!!!! Link to comment Share on other sites More sharing options...
digital_dreamer Posted May 17, 2006 Report Share Posted May 17, 2006 Guys, a 2-ohm resister will draw way too much current (12/2=6 amps) and will dissipate 72 watts of power (6*12=72). That would require a resister that can handle 200 watts continuously without thermal breakdown. No carbon film resistor will do.The brake and back tail lights donÕt draw that much power. I donÕt know exactly how much power each of these lights draw when fully lit up (you can measure the DC resistance of the bulb, but the resistance changes as it heats up), but they are in the neighborhood of 2-amps to as low as .5-amp. ThatÕs where the trial and error comes in Ñ whatever specification Volvo designed the lights and failure circuit for, we have to match them (minus the LED power draw).Some manufactures sell 6- to 25-ohm high-wattage wire-round resistors for this application. See superbrightleds for some ideas (bottom of page).Some of you who have already done this and succeeded in fooling the failure circuit, need to tell the others what the resistance you ended up with. Of course, you need to also tell us what LED application you used, too.Just the same, if you changed to a high-wattage bulb, then you need a higher wattage shunt resistor.regards,MAJP.S. IÕm not saying the 2-ohm wonÕt work. IÕm sure it will. You simply need to meet or exceed the amperage draw of the bulb to fool the circuit. What I am saying is that you could end up drawing excessive current if you use 2-ohm shunts for each bulb in the tail assembly. Excessive current draw leads to more power needing to be dissipated (which is wasted, by the way). Possible blown fuses. Fire. Lower engine performance due to alternator working harder. Yeah, I may be overstating my case here. :D Link to comment Share on other sites More sharing options...
Newbie Posted May 18, 2006 Author Report Share Posted May 18, 2006 Thanks Digital_Dreamer and all the PMI got the 100ohm 10W resistor for my license plate, 50ohm 10W resistor and they work beautifully for my brake light.I have old 96 850, so...may not be the same as your model. Link to comment Share on other sites More sharing options...
Che'_Moderator Posted May 18, 2006 Report Share Posted May 18, 2006 Thanks Digital_Dreamer and all the PMI got the 100ohm 10W resistor for my license plate, 50ohm 10W resistor and they work beautifully for my brake light.I have old 96 850, so...may not be the same as your model. :huh: Link to comment Share on other sites More sharing options...
Newbie Posted May 18, 2006 Author Report Share Posted May 18, 2006 Of course, I haven't forgot to thank you !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!IT is very "cool" to learn from the pro!!!!Thanks Che!!!! Link to comment Share on other sites More sharing options...
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