Low Fuel Light

[gungehead]

Hi,
I don't think my low fuel light is working. I am right down to nearly empty ( about 1/16th of a tank on the gauge) and no light on the speedo. I am expecting it to be broken now (well probably just not wired up).
How does it work? Is there a feed coming from the tank that earths/powers the circuit or is it a device that switches on when the voltage at the gauge gets to a certain level?
What is the best way to test it?

Thanks for your assistance.

Dave

PS it is a '62 3.8

[piman]

Hello Dave,

that light is fed by an auxilliary contact on the fuel level sender, white/green cable. The other side of the light is on the same fuse as all the rest of the ignition switched fuse so if instruments etc are OK then it's either the bulb or a poor connection or fault at the sender.

Alec

[gungehead]

Thanks Alec,
I presume the 4inch hole in the boot floor gives me access to the sender. It is not a tank off job like it is on my Midget?

How low does the gauge normally get before the light comes on?
Thanks

Dave

[ManxNeil]

In a 3.8 it seems to be on all the time!

Mine starts to flash on when going round corners with the tank just under half full and then comes on solidly when it's just under a quarter full.

[PPV]

Mine is eaxactly the same as Neil's and is a 3.8.
Regards,

[gungehead]

Thanks,
So mine, down at 1/16th tank, is way past the point that it normally comes on.

I will investigate...

Dave

[gungehead]

I have worked out what the problem is...

There was no bulb in the bulb holder.

There was no bulb holder either. Instead there was an LED wedged in the back of the speedo. The wires went into a modern loom. There were several other wires too with non Lucas connectors on them. Not sure what it was for but it doesn't look like it is working or even all still there! I don't know where the other end of the loom goes.

Just purchased a new bulb holder and about to fit it.

Thanks for your help

Dave

[ManxNeil]

That would explain that, then!

Well done, Dave. Presumably the previous owner was attempting to get round the problem of bulb failures in the instrument panel and the hassle of getting to them to replace them.

Cheers,

[ecosselynx]

Hi

Just for information, over the years on my car the low fuel light comes on with around 25 miles left in the tank.