Gas gauge not working? I think I fixed it.

Currently working on my 64 Valiant instrument cluster on the bench and dealing w/ same issues. I'll post more details in a new thread, but a few quick comments:

Pawned stated a few pages back that you can't do anything about the sensor's response, but not quite true. I added 27 ohm in parallel w/ the fuel sender on the circuit board (just ring terminals on studs) to get it to read correct at empty (where sender is ~90 ohm). I adjusted my new electronic Vreg ($30 ebay "voltage limiter) to get "F" to read correctly. For a 2-pt calibration you need 2 "knobs" you can turn. If too much signal (too low resistance at sender), you could add series resistance. Not sure why Pawned stated 9 ohm empty, since that should be when full.

Now fooling with the coolant temperature gage. Initially, the temp gage read open (infinite ohms), so I popped the top (drilled 1 rivet) and found the wire burned. I wrapped a very thin wire around the stub wire left off the arm, soldered and soldered the new wire to the output stud. The factory wire is likely Ni-Cr so I doubt solder sticks, but it does hold the Cu wire tight around it, but might not prove a long-term repair. The factory used pink adhesive at the stud, which I picked to bare Cu. With a 20 ohm resistor to gnd, simulating the sensor, the gage now reads at "ideal" mark (I think, 1st tic, just below half scale).

I am now searching for info on the sensor specs. Nothing in my 65 Dart shop manual, nor Haynes. Rockauto and others give conflicting PN's, even listing on/off switch sensors. I suspect most gage-type sensors have identical response and just vary in pipe thread and output connector. I put a TS-18 in my Dart (slide-stud connector), whereas my 64 Valiant has a threaded-stud type (can't read stamp). They read 318 & 363 ohm, resp. at 61 F. I'll post if I find manufacturer specs.