Dumb Electrical Question (LEDs)

[Natalya]

So the whole point of LEDs is to use less power for illumination. So you go and get LED turn signals and install them, but then the car is like, "Oh snap there's no resistance, a turn signal is out," and now you've got the quick blinks.

So you do what they tell you which is install resistors along with the LEDs and suddenly the car is like, "Oh okay it's all good," and your signals operate normally again.

My question is, "By putting in resistors am I increasing the current draw, and thereby using as much electricity as the turn signals were already using before?"

Also, I know that turn signals are not a major source of power consumption, but I like LEDs because they're brighter and stuff so I kinda want to replace all the lights.

[me and my metro]

They make replacement flasher units that disregard resistance and flash at a normal rate.

[NoD~]

They still use less power with a resistor in there, but the better way to do it is, as suggested, a different flasher relay. Actually, on my Neon, I was able to cut a small part of the circuit board inside the relay to kill the part that looks for the flasher resistance.

Another advantage to LED is the faster light up times ("Instant on" if you will). It's one of the reasons why my brake lights were changed out first in the Insight (the very small time difference could mean I don't get rear ended, or at least as bad). I haven't changed the blinkers out yet on said Insight because they aren't used enough (for me) to warrant the cost to replace them (Energy consumption wise). Headlights are my next big one to do. Soon as one of those blinkers burns out, however, replacement will be done!

[redpoint5]

The resistors will increase power consumption to nearly the same level as before changing to LEDs.

I don't bother changing the turn signal lights because they aren't used continuously, and are only on half the time when they are engaged.

My primary reason for changing the brake lights was to have faster activation time. At freeway speeds, the faster activation time can give drivers behind another 20ft of stopping distance.

Finally, I like not having to ever replace the bulbs. I'll never get pulled over for having a bulb out.

[oil pan 4]

I didn't need a resistor.
Stupid new vehicles.
What I was able to get away with was tossing the thermal flasher unit and putting in a capacitor based heavy duty flasher, LEDs in back plus on the sides and leaving the front as regular bulbs.

[darcane]

Originally Posted by redpoint5

The resistors will increase power consumption to nearly the same level as before changing to LEDs.

I don't bother changing the turn signal lights because they aren't used continuously, and are only on half the time when they are engaged.

My primary reason for changing the brake lights was to have faster activation time. At freeway speeds, the faster activation time can give drivers behind another 20ft of stopping distance.

Finally, I like not having to ever replace the bulbs. I'll never get pulled over for having a bulb out.

Never?

While LEDs have long service lives, they do have a non-zero failure rate. I'm seeing more and more cars that were early adopters of LED lighting with individual LEDs burned out, or even an LED array that is no longer functional.

I've had to replace the CHMSL in our Tahoe which is an LED array. Of course, I've only had to do it once, and the regular bulbs have all been replaced multiple times.

I love LEDs, but they can fail.

[Natalya]

I'm already sold on LEDs because of brightness, cool factor, power consumption, and instant-on capability. I put LEDs absolutely everywhere in the Mustang, and now I've got some on the Insight. Eventually I'll have the whole Insight done (except headlights) as I did for the Mustang. Maybe I'll even do the instrument cluster bulbs, since I have to make some repairs on that anyway.