New style fuel gauges to old age fuel senders! I am using Omega Custom Gauges in my 1965 Falcon and originally when I put the car together I cut a hole in the original fuel tank to install the matching fuel level sender unit that came with the kit. The empty ohm reading for the new style gauge is 240 ohms and for full it is 33 ohms. No problem the fuel gauge is accurate and dependable.
Now my dilemma: I recently purchased from Rock Auto a new Spectra fuel tank with a built in fuel pump/sender (made in Canada) to run the EFI for the 5.0HO engine I installed. ( used an external fuel pump up to now with all kinds of problems - not dependable ). The new tank comes with the fuel level sender and fuel pump combo installed in the original position of the tank, however the sender is set with the factory 1965 ohm settings where empty is 75 ohms and full is 10 ohms. Now when connected and at empty, the new style fuel gauge reads half full, and full is off the chart.
There is one sure fire way to correct it and that is using a Fuel Gauge Interface Module #91012910 available from Speewaymotors.com for $129.99. This unit will convert any fuel gauge to any fuel level sender in any automotive product.
Researching the old google I found the cheaper way “my way” which is to use a 386 ohm resistor ($3.99) between the fuel sender and fuel gauge. This is supposed to correct the empty reading but the full reading may be a bit off, but hey, as long as I don’t run out gas I am good.
I just received the resistor and this IS NOT the fix that it is deemed to be, I have just cut a hole in my new tank and installed the matching fuel level sender that came with the gauge kit. If I did not already have the sender, I would have gone with the interface module. The resistor pegged the fuel level needle at the key off position for both empty and full. It was worth a shot for 4 bucks.
