6v Fuel Gauge in a 12v System?

[splitty]

My '57 bus originally came with a reserve tank and no fuel gauge. Years ago I put in a tank with a sending unit but never hooked it up to the gauge. I got this 6v fuel gauge that I tried but the needle totally pegged. Someone said use a windshield wiper rheostat to step the voltage down, but it still pegged. I even tried a 3v power supply and it pegged. Any idea what the voltage requirements are for that puppy? Will I have to yank the gas tank and istall a 12v sender and gauge? Anyone want to sell me a 12v gauge?

Thanks,
Splitty

[Speedy Jim]

See the Fuel Gauge article on my web site for info on gauges.

I believe the 6V gauge should work for you.
Was this one out of a Bus?

Does it peg with the sender disconnected?

What did the sender look like that you put in?
It must match the gauge type.

If you get a 12V gauge from (?), the sender may not be the
correct one for the gauge.

Speedy Jim
http://www.nls.net/mp/volks/

[splitty]

The gauge I have is 12volt. I'm not sure of the sender, it came out of a big rear window split window bus 66-68. It pegs if run through the sender on 12v and it pegs with 12v running through a 12v interior lighting switch dimmer at all settings and it pegs with a 3v power supply.

How do them things work? Is it like a potentiometer with resistance changes as the float slides up and down? Why is there no spark danger?

Walter

[Speedy Jim]

Yes, resistance changes as float rides up and down.
The vapor mixture in the tank doesn't have enough oxygen to
make it explosive, so sparking won't cause any problem.

With sender disconnected, gauge should read EMPTY.
If it does not do that, there is a problem in the gauge or hookup.

[splitty]

I have it wired from sender to gauge to power supply. Is this correct or should I go from sender to power supply to gauge to ground?

Splitty

[Speedy Jim]

See:

http://jvila.club.fr/vdo_how.html

[Speedy Jim]

See:

http://jvila.club.fr/vdo_how.html

[splitty]

Great diagrams! Thanks a bunch.

Splitty