Ebody sending unit wrong resistance value.

I installed a new sending unit and filled up with about 6 gallons of gas. I have no reading on the fuel gauge. I grounded the wire at the sending unit and the fuel gauge goes to full. I measure 190 ohms between the sending unit and ground. I read that the sending unit should be something like 9 ohms to 90 ohms. I'm guessing mine is 33 to 240.
If this is correct, does anyone know how to fix this? All I can think of is adding a resistor in parallel with the sending unit, or increasing the voltage.
If I add a resistor in parallel, I do not think the gauge reading will be linear.

make a long wire with alligator clips on each end & 1 end on the batt neg post and scrape other end on sender flat circular metal & see if you have continuity all the way up front. You wouldn't wanna increase voltage. A parallel circuit would not reduce voltage (think of Nacho's bulkhead parallel bypass or visualize the drive around lanes on either side of the main checkpoint at a border crossing. You'd wanna resistor in series (in the blue wire if we're on the same page) but I think it'd be a nightmare of experimentation to get the right resistor but I dont know electronics so no firsthand experience. I kept my 5/16 sender which worked fine & soldered in a bung in the bottom of the tank for enough flow for my app (my adv was I had a new Spectra tank). EDIT on second thought a resistor in the blue line to ground WOULD reduce voltage that the sender sees

Thanks, I also have a Spectra tank. And Yes, if I hook up a resistor in parallel with the sending unit, it will decrease resistance.So if I have a 240 ohm sending unit, and I place a 240 fixed resistor across it, it will decrease my resistance by one half. I just dont think as the float travels, it will be a linear reading on the gauge. I guess if this doesn't work, I replace the new sending unit.

I've heard nothing but bad regarding aftermarket sending units. You might talk to an electronics whiz. A guy directed me to call a guy at the local Radio Shack (on an unrelated issue) who is sharp on that stuff. A similar plan might work for you but I gotta feeling that it'll be alot of experimenting ahead of you. Holler how it (all) turns out. EDIT If I had my druthers I'd want it dead on at the lower end of the scale as I dont like hitchhiking

Funny, I went out to the garage to double check ground to battery neg,=(0.5 ohms), and I thought the same thing, if i'm going to add a resistor, I would want the "e" side to more accurate. I'll let you know.

Dixie has sending units made by the original vender, send that one back, and get the real thing from them.

If the resistance is changing with the fuel level (assuming a linear resistance change) and you add a fixed resistance in parallel to this variable resistance then the combined resistance will be non-linear.

Don't buy that China crap...call these guys.....www.tristarradiator.com

Quote:

---

Dixie has sending units made by the original vender, send that one back, and get the real thing from them.

---

That is what I would do as well for two reasons:
1) to get an accurate reading
2) Support someone who has gone to the trouble of trying to supply good stuff to the hobby.

As for being linear with a resistor in parallel, none of the 70s era Mopars I owned were terribly linear from the factory. Either the gauge plummeted to half tank and then took longer to get to empty or they took forever to get to half tank and then plummeted from there. You just have to get to know your gauge and what it means. The factory on in the Cuda never did go to full when it was filled and it still has a couple of gallons in it when it says empty, which is good.
Craig