I'm working on getting my gauges working. I wanted to start with the fuel gauge. I've referenced my service manual and tried to decipher the schematic. The fuel sending unit has one wire coming from it, on the machine and in the manual both. That's what confuses me, how can a sending unit just have one wire. Doesn't it need power going to it and also someway to send the info to the gauge? So all you electrical experts please help, how can I test the sending unit and the gauge to see if they're both functional? Most of the wires from all the sending units have been cut and removed prior to me owning it. None of my gauges work so I'm kinda starting from scratch. Thanks
That is a common way for sending units to work. That wire comes from the guage, and as the value the sender is reading changes, be it temperature, pressure, or liquid level, the senders resistance changes, through the sender to ground. To check a sender, take the wire off and ground it. If everything else is good, the guage needle will peg out.
Okay. Now I get it. I will try to to see if the gauge moves. Thanks.