Fuel Gauge/ Sending Unit Quick Question

[mattkenton]

I have replaced all the wires with new ones and have checked all the terminals. The gauge is still not reading very consitant.

Double check my wiring i provided please and see if i did everything right. I am going to load test the sending unit tomorrow. But i really think that it is the gauge. The sending unit is fairly new.

Oh and an after thought. My wire cluster that has a Black/Purple/Grey bundle. Are those Ground/Ignition/Tach wires? The big one in question is the black wire. Is it really a ground and does it need to be grounded in order for the ignition to work with the gauges. Thanks.

 

[Silvertip]

Re: Fuel Gauge/ Sending Unit Quick Question

If the GROUND you show in your diagram is battery ground (meaning it is an actual ground point not necessarily at the battery) then the system should work. Don't know what you mean by "load testing" the sender. You can measure resistance if you know approximately how much fuel is in the tank. Empty = 240 ohms, Full = 33 ohms, 1/2 full = about 109 ohms. The sender wire must be disconnected when you make the sender resistance checks.

 

[mattkenton]

Re: Fuel Gauge/ Sending Unit Quick Question

Resistance testing is what i meant. I am going to retest all of my grounds. The reason for all of this was that my full gas tank would only read at half tank. Then when i replaced all the wires and reconnected everything the gauge went to half tank again. Turned key off and on and then went to quarter tank. Again turned key and it went to empty. I am going to also remove the sending unit and test it while out so i can see what sort of result i get on the dash.