[TR] Lying Fuel Gauge

[Randall]

---- William Pugh <anabil007 at comcast.net> wrote: 

> If you remove the hot (green) wire the gauge should read empty??   Still reads
> full.  Correct voltage to the green wire.  So b& must be a faulty sensor ??

That is not correct for a TR3.  The TR2-3/A/B fuel gauge works backwards to the later gauges, open circuit (high sender resistance) is full on the early gauges.  If you short the sender wire to ground, the gauge should go to empty.

The other thing to watch for is the ground to the gauge housing.  Again the TR4-6 gauges do not care, but the TR2-3 gauges require a secure ground for proper operation.  Without a ground, the gauge may go to either peg, empty or full.  Although the factory apparently relied on the ground through the mounting bracket, I advocate adding a ground wire from the mounting stud (under the knurled nut, preferably with a star-type lockwasher) over to the ground tie point on the back of the instrument panel.

Same discussion applies to the sender in the top of the fuel tank.  I have added a ground wire from the ground stud on the sender down to one of the bolts that clamps the tank to the body.

Gauges and senders do fail, but check the simple things first.

PS, I haven't read the entire thread, so my apologies if this was already covered.

Randall