Electrical Fuel Gauge Problem

Discussion in 'Classic Mustang Specific Tech' started by bnws, May 5, 2013.

  1. fuel gauge needle pinned to left of gauge - I am getting voltage into cvr and pulsed voltage at gauge (measured w/ test light) . Grounded lead at sender and needle went to full, then hooked up a spare sender, ( out of vehicle ) with arm in full pos. dash gauge reads 1/2 with arm half way reads on E with arm at low end reads pinned to left of E on gauge. Is there a way to adjust needle position, or does it seem like a faulty gauge? Any input would be appreciated, thanks in advance.
  2. What peak voltage are you getting out of the cvr? It may be enough to peg the gauge when going straight to ground, but not enough to properly supply the gauge-sender circuit. I have the same problem you are describing and was told to replace the cvr. I have not done so yet, so I cannot say whether it helped.
  3. pulses from 0- 3, 3.5, shop manual says 0-10. I then did a continuity test from that lead (from cvr) to ground, and got continuity, don't think that's right ?
  4. It should be about 5 volts. I don't know one way or the other on the continuity issue.
  5. Is it original gauge and sending unit (or Ford stuff)? I replaced both with after market stuff, I think I had a GM gauge and the voltage scale it required was different. I got a Ford gauge (both were autolite). I think it requires a linear scale and the sending unit sends a a non-linear signal (or vice versa). I get full and empty correct on the gauge, but in the middle it is not correct. It is close enough for me, but it is still annoying.
  6. original gauge, original cvr, replacement fuel tank sender, But I rigged up original sender (replaced some time ago, had bad float, thought sender was bad ) anyway I got results listed on original post. Note, gauge has been working fine for past couple of years w/ replacement sender