2005 150 FS & Fuel Management Wiring

[Outbound44]

Hi Guys -

At the end of last season I launched a project boat that I was working on for quite some time. Its a 1973 21ft Boston Whaler Outrage powered by a Yam 150 FS. I have the fuel management guage installed however its not wired to my tank and does not display my fuel quantity.

I would like to know if anyone know's how to wire the guage to the sending unit on the tank & if I will need any additional harnesses,ect to do so.

Thanks!

Bill

[boats.net]

The fuel management gauge does not have a fuel gauge in it only the multifunction speedometer has the fuel gauge. If you have Speed/Fuel combo gauge then connect white wire on speedo to fuel tank sender wire.

[Outbound44]

Thanks for the reply.

It is the speed / fuel combo gauge.

I tried connecting the white wire to the sending unit and still not getting a signal????

Thoughts????

Bill

Fuel measurement

I may be too basic here, but get hold of a multimeter (ohm meter).

Disconnect both wires of the fuel level sender. Measure the resistance between the two wires coming from the fuel sender.

If it is a european style sender, it will read 0 ohm when tank is empty and 180 ohm when full. An american style sender will read 240/33 ohm respectively.
If your tank is about half full, a mid range reading should confirm that your sender is not dead, i.e. has a broken wire inside.

If you read an infinitely large resistance, your sender is broken, or you have a bad connection between the sender and the dashboard end of the wires.

If the resistance/continuity test passes ok, then make sure you connect one wire to ground, and verify that the ground connection point is good.

If this doesn't help, you can test the dash instrument.
To test the yamaha instrument, get hold of a resistor somewhere between 80 and 150 ohm (ideally, say 100 ohm), and connect it between the white wire and ground (to mimic a realistic position of the sender).
A potmeter (variable resistor) valued between 0-100 and 0-1000 ohm (the best match is a 0-470 ohm) should also give you a rough mimic of a working sender through the whole range.
This will verify the dash instrument without the uncertainty of the wiring and the sender.

Finally, to make sure you get correct readings, find out whether your sender is 0/180 or 240/33 ohm, and set the dip swithes on your instrument accordingly.