Hi there,
I am having some problems getting my fuel guage to work. I recently had my gas tank boiled out, cleaned and coated with plastic super snot. At this time my fuel guage was not working (it never worked). When I pulled the fuel guage sending unit, I check it on an ohm meter - totally open. I ordered a new fuel guage sending unit. Before I installed the new fuel guage sending unit, I checked it with an ohm meter - worked fine. The range was between 15 ohms and about 90 ohms. I installed the guage, hooked up the positive wire and hooked up the ground wire. Filled with gas - no luck. The meter was still at Empty. I double checked to see if the guage itself was operating by shorting the positive fuel guage sending unit wire to the fuel guage itself and it deflected nicely towards 'Full'. I released and it went back to Empty.

Is there something I am missing in setting up the fuel guage? When I got the new guage, I put that rubber boot thingy on (I simply mimicked how the old one went on) - did I miss something with setup. I am pretty low on gas right now, so when I fill up soon, I want to see if the float is moving by measuring the resistance after I put some gas in. Right now it's around 82 ohms. I imagine the resistance should drop as I put more gas in. Am I taking the right course here?

Almost forgot to mention, it's a 70 F250 4x4 with the in-cab gas tank. Thanks!

 

There may be a problem with the terminals on the wires, or the voltage stabilizer in the dash could be bad. The sender sounds like it works properly.
I am running around with a similar problem in my 69, except that the gauge reads 1/2 tank at all times. I haven't dug into mine too much, because the wiring is junk.

 

If you don't care about keeping your fuel gauge 'stock' you can install an aftermarket gauge. If you decide to do that, just make sure you get a gauge that's calibrated for your sender. I believe that Ford differs from GM and Chevy, and some aftermarket gauges are made specifically for use with the gauge maker's own peculiar sender... Anyway, do your research.

Good luck with it.