Low Fuel Light Stays On?

[jeffdemara]

I just switched all my gauge cluster lights to the blue led's. Looks awesome!
I plugged everything back in, and now the low fuel light stays on (i have half a tank).

Anybody know what the problem could be?

 

[88YotaTurbo]

Maybe you forgot to plug something in. Have you checked that? Or maybe it's something more complicated like the resistance difference between the standard bulbs and the LED's are causing it.

 

[jeffdemara]

Everything is plugged in. Taken it out 2 or 3 times now.
If it is a resistance problem from the new led's, is there any way to eliminate that?

 

[Dan_Gyoba]

LEDs, being solid state are more of an on/off thing. They're either on or not. The sender for the low fuel light is much more in the analogue domain, so a filament lamp is much more suited to it.

What you're going to need to do to leave that as an LED is to implement a circuit, probably a comparator, to tell when the light "really means it"

The downside to this is that generally the low fuel light kind of fades in/out for a bit before it's on solidly. During this period of time, you'll see the light blink on/off fairly suddenly. This could be a good thing, in that you're more likely to take immediate notice of it, but more likely it'll just be annoying and distracting.

 

[88YotaTurbo]

Here is the wiring diagram for the circuit. It shows what he was saying.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/Main/Main_137.gif