Fuel Gauge issues

[Zeph78]

Ok, when I first got my car, it had a check engine light for fuel level sender. When I was redoing my exhaust, there were 3 wires from the sending unit that were melted to the tailpipe. I cut out the melted section, and wired it back together. I'm not getting a check engine light now, but the gauge is stuck on "Full." I guess when the wires were melted together it shorted out the sending unit? How can I troubleshoot this to determine what's wrong?

[fastblackmerc]

Ok, when I first got my car, it had a check engine light for fuel level sender. When I was redoing my exhaust, there were 3 wires from the sending unit that were melted to the tailpipe. I cut out the melted section, and wired it back together. I'm not getting a check engine light now, but the gauge is stuck on "Full." I guess when the wires were melted together it shorted out the sending unit? How can I troubleshoot this to determine what's wrong?

I think you need to pull the sending unit / pump assembly out and work the float to see if the needle moves.

[Zeph78]

I think you need to pull the sending unit / pump assembly out and work the float to see if the needle moves.

Well, I have run several tanks of gas through it (and the needle never moved), so maybe the float is stuck in the full position?

[fastblackmerc]

Well, I have run several tanks of gas through it (and the needle never moved), so maybe the float is stuck in the full position?

Possible............

[Windsor58]

Were you getting a P0460 code?

[Gryphonzus]

Or you could hook up another sending unit and see if it works, if it does then replace the old one.

[FordNut]

Maybe the wires are melted in another place and the insulation is gone, letting the wires short out.

[Windsor58]

Also check out TSB 05-11-3, about P0460 DTCs. Just says to reprogram the PCM with a newer version (don't replace any HW), but only applies if you are just getting P0460. If you get other codes (not including P1000 which is just a generic that comes up with the P0460), this TSB doesn't apply.
And, of course, this does not fix the gauge reading full all the time. Just the P0460 DTCs.

[Windsor58]

Here is that TSB, (if I did it right...).