Fuel gauge woes.

[InimiaD]

I've got all the electrics working (and a load of extras) on my woody project, but the fuel gauge doesn't want to play, properly.
The fuel sender is new. part no 21A 303 made circa 09 / 73. I couldn't get a reading at all until I added a seperate earth from the sender to the chassis.
There's about 9ltrs of fuel in the tank and the gauge reads 3/4 full.
I've changed the fuel gauge and the voltage stabiliser, but the gauge still reads incorrectly.
I've no idea what the speedo is off, it's just one i had spare and fitted it just to fill a hole in the dash. The script on the speedo is SN4421/00SA. 1248. I chose this particular speedo to compliment the speedo drive gears in the g/box.
The temp gauge works fine, so at least that is compatible with the stabiliser which is a 4 pin type.
I'm guessing I need a suitable voltage stabiliser to match the sender unit.

What do you electrical gurus suggest I should try next.

Thanks in anticipation.

[dklawson]

From the Somerford web site:
21A303
SENDER UNIT, fuel gauge, screw-in type 1
Up to 1964; models without voltage stabilizer.

and

AAU8340
SENDER UNIT, fuel gauge, screw-in type 1
1964 on; models with voltage stabilizer.

So... if you are using the fuel gauge with the wider, slow moving needle and using a voltage stabilizer, you want the AAU8340 sender, not 21A303. If your temperature gauge is using power from the existing stabilizer and the temp gauge is working fine... there is nothing wrong with the stabilizer.

[surfblue63]

If all your electrics check out OK then try bending the sender arm.

[InimiaD]

Thank you for the answer Doug.
School boy error on my part. I've been reading the topics / threads regarding stabilisers, gauges etc, but it didn't click with the grey matter that the same applied to the commercial variants..

I've got the correct one on order Stu.

Time to sell the other sender unit on I reckon.

[InimiaD]

New sender fitted earlier and the gauge is now behaving itself. Sorted.