Pennywise said:fo'runner, Good job! This probably is the cleanest install for those of us who are looking for parking and brake lights only, however I think that there may be one major problem with this method, the total current draw.
The stock brake lights are 27W and if you use the 4157, they have an output of 27W as well. Doing the math, you have 4 bulbs with output of 27W, resulting in 108 W, and resulting in a current draw of 9 Amps. Since this all falls under the stop fuse at 10 Amps, it is already within the red zone. Actually, there are other other items (on the schematic) such as shift lock control ecu, engine control ecu, suspension control ecu, etc. that are not even figued in with this total current draw. These computers probably function in the mAmp range, but this will quickly add up. Although it seems like the perfect method to wire the bumper lights for brake/parking only, there may be other apparent problems.
Please let me know if my line of thinking is correct. I am trying to sort this all out and just want to make sure that, in the end, my wiring is NOT protecting my fuses...
Tom
AlexJet said:What about LED in this mod? I'm doing this mod in the same way as fo'runner did. If I'm using 4157 LED for parking/brake only, would it be the same wattage and current? I thought by using LEDs we lowering electric consumption, so current should be lower the 9A with the same wattage.
Correct me if I'm wrong.
Pennywise said:AlexJet,
Leds would be ideal for this situation, since they produce very little heat, but typically they would not be as bright as a standard filament bulb. They don't market discrete leds (or led based bulbs) in wattage, but usually in mcd (millicandela). There are some complex equations to convert mcd to lumens. After doing a quick search, I came across this site, http://www.gizmology.net/LEDs.htm, which states that a 100 W bulb produces about 1700 lumen. He also states that the bulb would be about 135,000 mcd if the light was radiated equally in all directions. This gives you some rough numbers for comparision, but the best way to do it would be to try a particular bulb out and see what you get.
I have been purchasing some leds lately and have been trying to make some of the wedge based bulbs (194). I have had several done, but was not really impressed by the overall *brightness*.
One of the problems that you would run into is that I had a hard time fitting a 4157 bulb into the housing, so I had to sand down the inner walls of the bumper lens to get it in. So, the diameter of the bulb cannot be larger than an 1" or so (I don't know the actual size). Those small light tower bulbs may do the trick. They are fairly thin and just stick further into the lens with most of the leds on the side. However, at $25 each from (www.autolumination.com), it isn't worth it. You could always try it out and if it doesn't work, return it. I returned some items from this guy and he charged me a 20% or so restocking/retesting fee.
As for current draw, it would depend on how the leds are wired internally. Now if you build them yourself, you know exactly the total current draw. Since the forward voltage drop on red leds is about 2V each, you could get 5 of them in each series circuit drawing 20 mA. Therefore take the total number of leds, divide by 5 and multiply by 20 mA. This is an approximate value for current draw from this single led bulb. There are a number of variables, so these numbers should give you an idea. For comparision purposes, the stock 194 bulbs take about 250 mA.
I think it possible to put wedges in the bumper lenses, but I don't think it would be bright enough to bother. If anyone did this, please speak up and let us know.
I hope this clears things up a little. I have just started tinkering around with this stuff, so I guess we're all in the learning process.
Tom
AlexJet said:I'm doing this mod right now. Yes it fits just tight enough. As soon as finished this, probably tonight if nobody will disturb me or tomorrow evening, I'll post some images.
BTW, I measured the draw by multi-tester. It's 34mA on tails and 94mA on brakes, so total maximum on brakes will be less then 0.2A which is good and I do not need to worry about fuses.
HRunner said:Hey guys, bought the 1157 socket today and prepared to do this mod... however, there's no instruction in the package...
Sorry hope this is not a dump question, which one is ground? which one is what? Please help~
(Sorry I was studied ART....)
![]()
![]()
Pennywise said:Hmmmm....
Not exactly sure what the problem could be, I'll have to think about it some more.
One thing that you could try is to test the bulb in the following conditions right off the battery: tail only, brake only, tail and brake. This would isolate the problem slightly and tell you if it is the leds or if it is some combination of the leds and stock lights.
Keep us posted and If I think of anything else, I'll let you know.
Tom
AlexJet said:Ooooops, I have a PROBLEM!
OK, I've done the lights, insert LEDs. Then I wired them to the rear taillights. I've found the connectors for the tails and for brakes. Wired to tail half power LED output and full power connector to the brake connector of taillights. Then tried it out. Looked like everything is fine. Taillight + bumper tail looks nice and really match to the bulbs in tails. Then becoming a problem. When pressing brakes they go completely off. I double checked everything: connectors, housing, all in place. Tried again - same result: tails working braking not working at all. After all I started to check out electric part and figured out that they work ONLY tails OR brakes. That was my RIGHT light. OK, I decide to leave tails only for a time while I'll figure out what was wrong. I wired LEFT in the same way as right (only for tail). S***t it's not working. My left tail works only when BOTH connectors tail and brake are connected to the taillight housing. But in this combination it's switches off when brakes.
So I'm shocked and stopped. Why? What happened? What's wrong? Why two lights work differently?
fo'runner said:I explained this problem in one of my earlier posts.....I believe my writeup is 2/3's of the way down on page #12--> http://www.toyota-4runner.org/showthread.php?s=&threadid=1137&perpage=15&pagenumber=12. The exact same thing happen to me on one side of my installation. In that post I stated you have to make darn sure you have a GOOD ground for the brake lamps to work. If you do not.....then the tails will work but not the brakes. Remount your ground wires to a different location.
fo'runner said:I explained this problem in one of my earlier posts.....I believe my writeup is 2/3's of the way down on page #12--> http://www.toyota-4runner.org/showthread.php?s=&threadid=1137&perpage=15&pagenumber=12. The exact same thing happen to me on one side of my installation. In that post I stated you have to make darn sure you have a GOOD ground for the brake lamps to work. If you do not.....then the tails will work but not the brakes. Remount your ground wires to a different location.