Fuel Gauge Problems

[Geno53]

The fuel gauge is not working on my Beneteau 35. I was wondering what would be the best way to check for the problem. It seems to me that it has to be one of three things, the tank sensor the wiring from the sensor to the gauge or the gauge itself. Is there anyway that the gauge and the sensor can be tested? If a multimeter would work how would you set it up?

Any suggestions would be appreciated.

[delmarrey]

The best way to troubleshoot the problem is to pull the sensor from the tank. Make sure it is physically operating properly. Put and ohm meter across the terminals then move the float. There should be a constant increase and decrease as you move it up and down.

If you suspect it to be in the wiring, you can remove the gauge as well, and do a bench test by hooking the gauge to the float unit. You just have to make sure you get the wiring correct.

Most gauges have three wires: Ing., sender, and ground. The Ing. will be the Pos. lead to the Batt. and the ground FROM THE BATT. SHOULD go to the FLANGE of the sending unit.

The ground on the gauge (a black wire) should go to one of the terminals on the sending unit. And the Sender wire (usually pink) should go to the other terminal, sometimes marked but normally doesn't matter.

Enjoy.........................._/)

[GordMay]

Excerpted From “Basic Engine Gauge Theory & Testing”, at: http://www.cruisersforum.com/showthr...=&threadid=645

Testing Fuel Gauges:

1. Disconnect Pink Sender Wire from Gauge, and turn power ON.
The Fuel Gauge should read ZERO Scale (< Empty)

2. Short the Gauge Sender Terminal to Ground.
The Gauge should read FULL Scale (> Full).

3. Measure resistance of Pink Sender Wire to Ground.
American Floats: 240 Ohms (Empty), 103 Ohms (½ Full), & 33 Ohms (Full)
European Floats: 10 Ohms (Empty), 95 Ohms (Half), & 180 Ohms (Full)
Automotive & other Float Switches may use other resistances such as 0 - 90 Ohm, 73 - 10 Ohm, & etc.

4. Disconnect Pink Wire from Sender at fuel tank.

5. Test continuity of Pink Wire.
Zero Ohms from Tank End to Gauge End - If not, repair or replace Wire.

6. Measure Resistance from Sender Terminal (on Fuel Tank) to Ground on Tank.
Should read as per (3) above - If not, replace Sender.

HTH,
Gord May

[Matt Hager]

I just repaired mine. I had to take it apart to clean it well. The wire windings that the float arm ran accross to change the settings were full of crude. after a good cleaning I again got the proper resistance readings.

goodluck,

matt

[Alan Wheeler]

First thing to check is voltage. No point taking everything out if the problem is just voltage supply.
Then follow Gords step by step guide.