1972 Fuel Gauge Ohm range

[tac27]

I'm replacing the fuel tank for a '72 914 with a 8 gallon racing cell; this includes a new fuel sending unit (a six inch unit as the stock unit is too large for the cell). The manufacturer (Fuel Safe) has asked that I verify the ohm range of the stock gauge prior to ordering the sending unit. Anyone know off hand what the ohm range is, from empty to full. I've had one answer of 0 for full and 90 for empty but want to verify.

Thanks.

Edited May 27, 2008 by tac27

[Stephen Jacobs]

Very close, 0 Full - 90 empty, slight variations by a few Ohms here and there.

 

One thing to remember is that it is all relative.

 

I would rather have a gauge that read empty before the tank was than one that showed it still had a 1/4 of a tank, and I am stuck on the side of the road.

 

Reason why I say it is relative is that there are at least four places for variations to effect the readings.

Sending unit - its just a big variable resistor.

Wiring, as it ages the Ohms increase - hopefully it never goes to infinity.

The gauge electromechanicals, these tend to have issues as they age, especially the resistor

Then the needle itself and the gauge faces.  Needles can be placed any where on the plane because the shaft is not keyed.

 

Hope that helps