FI light stays on after replacing with LED

[Ziffer]

I decided to replace all my bulbs (except headlights, haven't gotten to those yet) with LEDs, including the dash. Some dash bulbs were burnt out, but I don't know if the FI warning bulb was burnt out or not. It wasn't on before I replaced it with an LED. But now it stays "half" on. What I mean by that is, when I turn the key on, the FI light comes on bright. Then once the hum (fuel pump?) stops, the FI light dims, but doesn't go out. Bike seems to run great. Is this a normal VFR thing that happens when you switch to LEDs? Anybody have this happen to them? 

 

2000 VFR800... Yeah, baby!

[raYzerman]

I did the same, need to go back to an incandescent bulb...... unless you happen to like the thing on all the time.....

[Ziffer]

10 hours ago, raYzerman said:

I did the same, need to go back to an incandescent bulb...... unless you happen to like the thing on all the time.....

I don't like the light being on all the time, but I might be willing to live with it to keep my LEDs.

 

But after thinking about it, I don't think it SHOULD be on. That circuit shouldn't send power through it unless something is wrong. I'm thinking bad ground or something back-feeding through the circuit for some reason. Possibly something wrong with the FI system, but not necessarily. Any other ideas?

[Grum]

5 hours ago, Ziffer said:

But after thinking about it, I don't think it SHOULD be on. That circuit shouldn't send power through it unless something is wrong. I'm thinking bad ground or something back-feeding through the circuit for some reason. Possibly something wrong with the FI system, but not necessarily. Any other ideas?

 

The FI light is unique compared to the other indicator lights.

 

The ECM provides an electronically controlled ground to the light until the Fuel Pump prime is completed. It also provides a pulsed ground for any fault codes.

 

As you didn't have any issues with the previous bulb, and as raYzerman has had the same issue using an LED means the circuit is not designed around the very small different current draw an LED compared to the original incandescent bulb.

 

You might be able to experiment with a resistor arrangement either across and/or in series with the LED ground side to mimic the load of a normal globe so that after Fuel Prime its just at cutoff. Or simply do as raYzerman did, fit a new normal globe only for the Fi position, it will probably last a lifetime with a conventional bulb anyway.

[raYzerman]

I had read some time ago maybe in the other sandbox where somebody had the same issue.... so that's 3 of us.  The next time you have the front cowl off, swap it out for the old bulb.  The rest can stay LED no problemmo...... I haven't yet....

[Tirso]

 

25 minutes ago, raYzerman said:

I had read some time ago maybe in the other sandbox where somebody had the same issue.... so that's 3 of us.  The next time you have the front cowl off, swap it out for the old bulb.  The rest can stay LED no problemmo...... I haven't yet....

 

KevCarver had the same issue with red led for Fi.

https://www.vfrdiscussion.com/index.php?/forums/topic/93624-pre-refurb-questions/&tab=comments#comment-1107966

 

I did what he did, used regular bulb for Fi, installed LED's and now have a "Super Blue LCD Screen"

From Kev's post:

[DannoXYZ]

You can mimic incandescent bulb with LED by adding ballast resistor in parallel so combined impedance/load is exactly same as original bulb. Pull out multimeter and measure resistance of original bulb and LED. Then get resistor so combined is same.

 

1/Rt = 1/R1 + 1/R2 , so

1/Rincandescent = 1/Rled + 1/Rballast

1/Rballast = 1/Rincandescent - 1/Rled

1/Rballast = X - Y

 

plug in X & Y from measured values and flip it

[raYzerman]

That's a good fix in another application....... however, this bulb is in a twist/turn socket that installs into the instrument panel circuit board...... would require some more creative solution.... meh, just put in the original #74 incandescent...... 

[Ziffer]

Thanks for the replies. It sounds like the ECM provided ground is probably where the issue is. I'll think about it some more...then maybe go back to an incandescent bulb. I still don't quite get it. After fuel prime, and without fault codes, the incandescent bulb had enough resistance for the ECM to read? I just don't understand why/where the current is coming from.

 

Oh... If the ECM is providing the ground, then the circuit is normally hot, and needs a ground to light up. So there is a low-grade (or high-speed intermittent) ground somewhere, possibly caused by the ECM.