My name is Joel I am working on a cat 231d with a fuel gauge problem. Serial # MPG 000894 The gauge shows full all the time. I disconnected the plug at the sender, ohmed the sending unit while moving the arm in the tank. The ohms went up and down as would be normal. Does the ecm supply ground to the sending unit? The return wire ohms coming from the sender right before the ecm are only around 3 ohms. What values is the ecm looking for from the sender?
On some (Faria) fuel gauges you can sweep a magnet across the gauge if it sticks on full. Not sure if that's your problem though. I thought the gauge in my skid steer was bad but I think it's just the top portion of the fuel tank is so much bigger than the bottom portion the float doesn't move as fast. A full tank goes for 10 hours but half a tank only goes 2 1/2 hours.
1. The float is stuck. 2. The meter pointer stepper motor is broken. After checking the above two items, try
The black wire should be chassis ground. The green wire goes to the monitor. Depending on which way it works, unplugging the sender should make the gauge go one direction, shorting the wires at the harness should make it go the other.
I have moved the float while reading the ohms at the sending unit. The ohms rise and fall when the float is raised and lowered by hand.
The chassis harness wire colors before the sending unit plug are black and white. The wiring diagram shows the colors to be black and green. I would like to check the chassis harness wires going into the rear of the cab and ohm them. Does anyone know the wire numbers at the cab?
Check your message inbox for an electrical schematic.
@ Nige check PS 53392
Gotcha. Thanks. To the OP. Check your messages.
I got the schematic. I already have the copy from Cat. The wire numbers did not seem to track. Just wanted to make sure I was on the right track. thanks