This may seem a little simple but why not instead of trying to figure out
the resistance required to fix it, try using a pot or variable resistor. And
on the next fill up adjust it to full and see if it reads correctly down the
scale. This should work unless the gauge is adding resistance and needs
>From: "Jim Altman" <email@example.com>
>To: "'Malcolm Walker'" <firstname.lastname@example.org>, <email@example.com>
>Subject: RE: Gas Gauge Oddities
>Date: Sat, May 27, 2000, 9:51 PM
> You need to find the resistance required the guage read full using the
> method David described. Then use an Ohm meter to measure the resistance of
> the sending unit when set to full. If the resistance needed is greater than
> the sending unit actual resistance then (resistance for full reading on
> gauge) - (resistance of sending unit)= resistance needed in series. If the
> resistance needed is less than the sending unit at full then make
> (resistance needed)= R1 in Richard's formula and solve for R2 which will go
> in parallel.
> Jim Altman firstname.lastname@example.org Illigitimi non Carborundum
> http://www.altlaw.com/metro/jaltman.html 69-TR6 76-TR7 80-TR8 W4UCK
> -----Original Message-----
> From: email@example.com
> [mailto:firstname.lastname@example.org]On Behalf Of Malcolm Walker
> Sent: Saturday, May 27, 2000 2:37 PM
> To: email@example.com
> Subject: Gas Gauge Oddities
> I'm trying to get my fuel gauge to work properly. Before, it would
> always read 1/4 tank if the level was > 1/2 in the tank, and read
> properly below that (although sometimes it would read 3/8)
> I've got a new(er) tank sending unit from a TR6. Now, (just by putting
> the sender into the circuit and holding the float at its limits) I get
> correct readings for Empty but Full puts the needle pointer at just
> below half.
> Any suggestions? When I pull the sender out of the circuit and short
> the leads (~0 resistance), it reads just under 3/4 tank. So either
> something's too resistive or something's not getting enough power.
> Where do I start?
> Thanks in advance...
> To know that which you do not know, is the best.