OK - disconnect the wire from sending unit - check what resistance reading is for the sending unit - if disconnected you are getting the 13.5 ohms, that is a signal for FULL to the gauge. If it is only 1/4 tank the reading will be more like 50-60.
I'm going to go fill the tank up an take another reading an see if something else happens I get back in bit these old babes are simple cars to work on but lift!e issues are mind boggling sometimes
You should remove sender and and test now. Fuel gauge is a simple circuit, adding gas just going to complicate things. Also measure second unit and see what it reads, moving float will vary resistance(or at least should). ,
13.5 is around the ohms to produce a full reading, which is why you are seeing the full reading on your dash. I agree - don't add any gas. Since you said the unit is new, this might just be a case of the float arm bent wrong to fit your tank. Pull the unit, test it in its full range and see if it falls into specs. If it tests wrong, replace it. If the unit works correctly, fit it to the tank so the float arm is properly located. In the past couple years I have had several "white box" new senders that were faulty. Ended up going through several to get a good one.
I think you guys are right, I did put gas in an retested it it came to 7.0 ohm's I have a new one in a box pulled it out tested it it's right on specs its quite possible when it was installed that maybe it was not positioned right in the tank? Anyway I get a electric fuel pump off my friend an drain tank an try new one any pointers you can let me know about when installation of new one would be appreciated an thanks again for your help.
Glad you are getting closer to the fix. Unit only sets in one way with 2 offset notches so it is tough to get it wrong. I put a little Permatex high tack gasket sealer in the groove for the o-ring to hold it in place while assembling. Been doing it this way for 40 years with zero problems.
Thanks for everyone input here you have been great help and thanks to Craig the Indiana state rep the fuel Sender unit #3 lol were all defective the new one works great no issues an no more driving worrying if going to run out of gas
Now you know why I ask lots of questions trying to diagnose the problem....not just sell parts one does not need.
A little late to chime in now but for future, I also had problems with the aftermarket sending unit, I finally gave up on it. I did the following and it cost nothing, took less time than all the screwing around with aftermarket ones, it has been working flawlessly for a year now. They usually don't fail, they just get dirty and lose continuity between the wiper and the winding, giving you the good old "E" You can check the wiring and gauge by removing the plug and sticking needle nose pliers in the terminals, the gauge should go to full, if it doesn't, check the connection at the sender plug for corrosion, muriatic acid will clean it back to new in about 1 minute, if it still doesn't work you have a broken wire or a bad gauge, if the gauge and wiring check out do the following: 1 - removed the cover over the winding of the OEM sender 2 - soaked it in some muriatic acid for a minute or two, just the windings not the wiring pins or pivot bushing 3 - spray with brake clean or contact cleaner after soaking to remove acid residue 4 - tested resistance values, works perfect right 5 - reinstall windings cover, plug into wiring harness and check gauge for empty and full position, if it works install in tank , if it doesn't, sorry for your luck, and the best of luck with an aftermarket one.
