gas tank gauge reading wrong

[marcia drake]

Hi BAC members:we hope someone might be able to help us: our fuel gauge has not been reading correctly for a while--now in GA for service: changed the sending unit and also the fuel gauge with NO results... the wiring has been checked... any ideas for a fix?? thanks  Charlie & Marcia Drake

[Ken Buck]

A wire with brokens insulation and corrosion. The sender works by varying the ground side of the circuit. If you put a new tank unit and a new gauge on and have exactly the same readings/problem, then the problem is the wire in between. Find and cut out the bad section or replace the wire altogether and hope you can get your money back for the new parts that didn't work.

The above answer assumes no odd readings on any other gauge. If you have multiple gauges reading improperly then you may have other dash ground problems or voltage supply problems. And that's a whole different problem.

[Gerald Farris]

Charlie & Marcia,
The key to repairing any gauge problem is diagnosing what the problem really is in the first place. A good mechanic never throws parts at a problem until he knows what the problem is.

Since you did not state what year and model your coach is, I can not say what problems are common to the fuel gauge circuit. However your technician is obviously not completely diagnosing the problem accurately. If the tank unit is good and properly installed, the dash gauge is good, and the wiring, power and ground circuits are good, the gauge will work properly.

There is something that your technician may not have considered, on some coaches the in dash engine monitoring computer also has a feed from the tank unit. Could you be getting a feedback from this circuit if it is present on your coach?

Gerald