[Fordy8man]

i built my truck on a 1987 bronco frame. im getting ready to wire up the fuel gage and i dont know which wire is what. the frame has the origanal gas tank and it has two wires coming out of it. Yellow and Black. which one is what. pos and neg.
thanks Tim

 

[302 Z28]

Black is always assumed to be negative (-), but there are exceptions. The yellow wire is the sensor.

Vince

 

[docvette]

Wires

Doc hereimp:

The black wire should be Tank to frame ground.

The Yellow should be Sensor Low, To the Fuel gauge.

There should be no POSITIVE wire at the tank at all.

The sender wire is a ground reference that goes through the fuel float/rheostat assembly that reports the status of ground with respect to "Hard " Ground. The less resistance to ground (0 ohms), the lower the gauge reports, the higher resistance to ground the more the gauge reports...

Your sender may not play with "Another" or different Gauge, due to resistance values at the Gauge, or be grossly in error...so if you have an after~market fuel gauge, your going to want to measure the resistance of the float with respect to the what the new gauge wants to see, and change the sender respectfully.

Hope it helps!

Docimp: