Service engine soon indicator

OK so the LED has the ~1K ohm resistor built in, that makes it easier. You will still need a resistor that is the same resistance as the bulb would be so that the computer sees the correct current. You could add a bulb in parallel with the LED but be forwarned that if that bulb does burn out, you will be pulling hair trying to figure out what is wrong. resistors are pretty much good forever.
I just spent 6 months chasing an intermitent P0650 code that was preventing me from getting plates. Unfortunately I learned a lot about the system in the process.
 
If I add a bulb, I need to figure out what specs the bulb is I believe. I'm clueless in all this.

Painless performance has a much larger light that has a 2-watt incandescent bulb, but the specs doesn't say the resistance.

So if this is what will work, I would either need to use the LED and find a bulb with the LED added up to 2 watt, or add a resistor.
 
Radio shack is still around but they have only a few store but they have a website that has decent pricing.
 
So a bulb that is 12V and 2 watt, will draw .16667 amps and have a resistance of 72 ohms.
So you would need a 72 ohm 2 watt resistor, I would use a 3W resistor or bigger as it will run at a cooler temperature. The ohms you will have to round to the nearest available which would be 75 ohm

Here is a niffy calculator for figuring these things out.

A 2W resistor will get warm so make sure there is air space around it.

I usually use either Digi-Key or Mouser for my electronic component needs.
Resistors are really cheap, it will cost more for the postage than for the parts, even if they just dropped it in an envelope with a stamp and mailed it.
Check around your local area to see if you can find an electronics supply place, or a place that caters to amateur radio people.
 
You could probably use a higher value resistor and it would still work, and run cooler. 500 ohm probably isn't high enough. You could get a few different values and try them- 100, 150, 200 ohm for example.
All at 2 watt or more (they will get warm when the light is on)
-Mark
 
I like the calculator. But not sure I understand it.

I just heard back from the company that made the harness and they said a 194 bulb is the best choice. From what I can find a 194 bulb has these specs

194 bulb.PNG


The calculator says. 37 ohms, .31667 amps. So I need a 37 ohm and maybe a 5 watt resistor?

Did some searching this morning, not really any electronics supply around here. I'll just order it. Amazon is pretty fast, I have prime so shipping is free, well kind of................



ses light.PNG
 
Voltage in the calculator should be 14.
That gives you a 52Ω resistor, 5W would be appropriate and will not get to hot.

In normal use that light is only on for a couple of seconds when you start the engine. But if there is ever an issue where that light needs to be turned on by the car it can be on for a while so you still need to be sure that your resistor workaround can handle it.
 
Thanks. Is there a tolerance on the 52 ohms? I've found 50ohms in 10 watt. Haven't found 52 yet.
 
In your case I woud round up to the next available resistance. It is very common in electronics to calculate the theoretical value of a needed component and then have to round to what is actually available.
 
Found some, but not in stock that I can find. On back order. I'll keep looking.
 
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