Which color LED bulb for amber lenses?

[Stevehose]

I want to put LED bulbs in the place of my blinkers and parking lights to reduce the current draw, I saw somewhere that you match the color of the LED with the lens or should I just go with white? I believe the bulb numbers are as follows: front/1157, rear/1156 rear parking/1895? and I want to do all the blinker and parking lights. Bonus question: which electronic flasher should I get to replace the stock one so theses puppies work or should I use resistors? Thanks.

 

[HB Chris]

Turn signals are pretty bright with the 21w bulbs and you wouldn’t need to change flasher. I used these LEDs for running and brake on NK and e12 and will put in the e9 as well. 1156 is single filament and I bought red. I followed Gary Waggoner and I couldn’t believe how much better these lights are.

 

[Stevehose]

Interesting, thanks. I am looking to lower the amperage draw, I can see that by turning on my parking lights that my volt meter drops from around 13.8 to around 12.9 so I'd like to lower that draw hence my desire to replace the incandescent for LED, not necessarily for the brightness difference.

 

[jmackro]

I am looking to lower the amperage draw, I can see that by turning on my parking lights that my volt meter drops from around 13.8 to around 12.9 so I'd like to lower that draw hence my desire to replace the incandescent for LED, not necessarily for the brightness difference.

Do you measure that 13.8 --> 12.9 volt drop with the engine running? I'd be surprised if your alternator couldn't keep up with the parking lights.

My guess is that any LED bulb is going to draw less current than an incandescent. If I'm finding the same product on Amazon (they seem to have changed the titles and prices since Chris took his screenshot), the specification says: Input Power: 0.05A @ 12V (About 3W). But, if power still equals amps X volts, .05A X 12 V multiplies out to .6 watts, not 3 watts. I think whoever wrote this specification didn't understand that while they may be as bright as a 3W incandescent bulb, these LED's draw far less current. 3 watts @ 12 volts would correspond to .25 amps, five times these bulb's rated current.

The Amazon listing I found was at: https://www.amazon.com/Everbright-4...words=ibrightstar+1156&qid=1614563012&sr=8-20 But again, I don't guarantee that these are the same bulbs that Chris recommended.

 

[Stevehose]

I don't remember exactly what the voltage drop is, but it is with the engine running, I will check again this week, but I do have an 85 amp alternator so you're right, it should keep up, maybe the old wiring is adding to resistance? If I use resistors, wouldn't those draw as much power as the incandescants? Apparently they get quite hot in order to trigger the flasher. I'd prefer not to use resistors and go with an electronic flasher if possible.

Do you measure that 13.8 --> 12.9 volt drop with the engine running? I'd be surprised if your alternator couldn't keep up with the parking lights.

My guess is that any LED bulb is going to draw less current than an incandescent. If I'm finding the same product on Amazon (they seem to have changed the titles and prices since Chris took his screenshot), the specification says: Input Power: 0.05A @ 12V (About 3W). But, if power still equals amps X volts, .05A X 12 V multiplies out to .6 watts, not 3 watts. I think whoever wrote this specification didn't understand that while they may be as bright as a 3W incandescent bulb, these LED's draw far less current. 3 watts @ 12 volts would correspond to .25 amps, five times these bulb's rated current.

The Amazon listing I found was at: https://www.amazon.com/Everbright-4...words=ibrightstar+1156&qid=1614563012&sr=8-20 But again, I don't guarantee that these are the same bulbs that Chris recommended.

 

[HB Chris]

Wow, I’m surprised the drop is that much. Clean your bulbs and contacts first.

 

[Stevehose]

Good idea, it's about time for a thorough run through

 

[jmackro]

I don't remember exactly what the voltage drop is, but it is with the engine running, I will check again this week, but I do have an 85 amp alternator so you're right, it should keep up, maybe the old wiring is adding to resistance?

Clean your bulbs and contacts first.

If the wiring, bulbs or contacts are dirty or oxidized, that would add to the resistance, which would reduce the current through the circuit. Ohm's law says : I =V / R, so more resistance = less current, which would give you less voltage drop at the battery, not more. But less current will make your incandescent bulbs glow dimmer. Since LED bulbs draw significantly less current, resistance in the circuit will have a smaller effect on their brightness.

If I use resistors, wouldn't those draw as much power as the incandescants? Apparently they get quite hot in order to trigger the flasher. I'd prefer not to use resistors and go with an electronic flasher if possible.

Putting resistors in parallel with your LED bulbs will allow your old-school, mechanical flasher to still work, but will draw a similar amount of current as incandescent bulbs. So yes, to achieve a savings in power, you need to use an electronic flasher, and no resistors, with your LED bulbs.

 

[Stevehose]

My lights are not dim but will clean anyway, it's time.

Ok thanks will look at the electronic flasher option

If the wiring, bulbs or contacts are dirty or oxidized, that would add to the resistance which would reduce the current through the circuit. Ohm's law says : I =V / R . So more resistance = less current. So you'd get less voltage drop, not more. You'd also get dimmer bulbs.



If you put resistors in parallel with your LED bulbs, that will allow your old-school, mechanical flasher to still work, but would draw a similar amount of current as the incandescent bulbs. So yes, to achieve a savings in power, you need to use an electronic flasher with your LED bulbs.

 

[jmackro]

Ok thanks will look at the electronic flasher option

Lots of threads here on e9coupe.com about e-flashers. See my post #15 in the thread at: https://e9coupe.com/forum/threads/flasher-relay.6507/ from 2013. Back then, I posted: "I installed an electronic flasher that cost $13 at a Carquest store last fall. The Carquest p/n was 7312. Other manufacturer's numbers are: CEC EF33, NAPA EL13, BUSS 233"