hi guys, just wondering if anyone has used these l.e.d. lights i found in oreilly
http://www.oreillyauto.com/site/c/de...d.s+%26+strobe

my oem brake lights make my interior lights dim every time i use the brakes, so i was wondering if i could replace them with some l.e.d. to have lesser watt drainage

 

I think you're approaching this backwards.
Before changing the bulbs (we'll assume that your current stock bulbs/sockets are in good shape) I'd look at the alternator and BAC and see why they aren't responding to the increased load of the brake lights.

 

yep, sounds like the charging system needs a tune up, not your lighting system a tune down.

this is especially true if you run a turbo model, your fuel system needs good voltage in order to operate properly. most people forget the fact that low voltage = low air/fuel mixtures which can cost a motor.

 

i had 2 of these i found when pulling a set of s5 tails and they sucked compared to the regular bulbs. possibly cause the diffuser was in still but regardless....if u want led just modify the taillights it'll be legit..u can use big like light led's or build your own for 20 bucks at radio shack. radio shack approach i might be doing soon that way there's no resistance issues

 

Yeah i have checked my B.A.C. and my alternator is new, i could just clean the B.A.C. again just to make sure but it does open up when i test it,
any other possibilities to check, I do have old battery cables cables that car has mounted, could that be a possibility

durtled- oh cool, whats the radioshack approach, and were the led you found in the tailights not bright at all

 

does it have an underdrive pulley set? what's the voltage drop to when idling with the lights on and brake lights applied?

the voltage should never drop below 12.6v no matter how many accessories you turn on.

 

My blaupunkt radio died every time I hit the brakes. The FC alternator is a joke, and it's my belief that everyone can benefit from getting an FD or Taurus alternator. And probably a larger battery.

FYI, I also started with replacing the brake lights with LED bulbs. That did help, but only patched my real problem. After getting an FD alternator, all my electrical problems were solved

I also pulled out the little light bulb inside the idiot cluster that warned me that my light bulbs were out. See, since the LEDs don't drop the same voltage, the brake warning light will come on every time you hit the brakes. If you install the load resistor, you'll have the dimming interior lights just like you did before...

 

The led bulbs I had put them in and they just didn't seem to work right made my brake warning light come all the time...I did a through inspection of how I was putting them in tried each pair of bulb sockets nothing seemed to make them work correctly. I chalked it up to 2 things 1 maybe s4 have some weird Independence issue. I remember reading a post where a dude went to tractor supply or someplace and bought some of the led trailer lights and moded his s5 housings to make both big circles filled up with the led looked real nice....but i recall he said something about needing to wire in some resistors but idk. reason 2 i came up with was it wasn't ment to be.

 

Yeah, let's go with that one.

 

the load resistors are to keep the turn signals from hyperflashing

 

That too, but it also prevents the "stop" light from illuminating every time you hit the brakes. Kind of counter-productive if you're trying to limit the load on the circuit ...

 

I bought some of those and went back to standard bulbs after about a week. I noticed they weren't instant on and would leave an annoying empty dark circle in the middle.

 

could also be the wire you are using for the yellow ignition wire or the acc(12v) wire. had similar issue had to pull acc off lighter plug and ground off frame to get mine to stay on

 

Karack- actually when i hit the brakes it doesn't lower my voltage, it just dims the interior lights, i guess i found my problem while at work, i deliver using my car and its been raining so i have to use the blower and defroster at the same time so my windows wont fog up, and i noticed that my voltage dropped to 12 so its not charging, what should i do to fix this, is it that the alternators 80amps isn't enough

 

More than likely, yes. Over time, your connections are just going to gain resistance, it's just a fact of life. You could spend hours cleaning all the electrical connections, i.e. battery, starter, alternator, fuse box, and still not solve your problem. As soon as I put an aftermarket stereo head unit in my car I started experiencing these issues. After the electric fan went in, it was just game over. I still highly recommend getting an FD alternator, you'll thank me later

 

karack- i tested what you said about turning on all the accessory's and it should not drop 12.6, what i did was turn everything on headlights, interior map lights, stereo, and even opened the doors to have the panel lights on, and it goes down to 12 volts, and its actually worst during the rain b/c when it rains and i only use the blower and defroster it gets that low (?.?)

what i did was check all my grounds and everything seems good, i used Aaroon Cake grounding procedures web site for reference and everything checks out good, the only thing i should do is replace the battery cables, anything else should i check? if its still like this then i should replace the alternator to a 100amp fd alternator, is not a main problem but i cant see when it rains