1 Fuel Gauge Mon Aug 17, 2015 8:18 pm
Howard64180
active member
OK, I decided I wanted a fuel gauge on my 1989 K100/2. Last time I had the tank off I fitted the harness for fuel and temp gauges. Then I was lucky to get a used fuel gauge off Ebay cheaply. It just needed the wires re-soldering. Before I go any further, I am sure the wires are connected correctly (searched for and found a clear picture to check).
The gauge is apparently not working on the bike. On the bench, when I connect a 9v battery across the terminals, positive to green/black, negative to brown, the gauge does not read. (The following will show it's actually trying to go backwards). If I then reverse the polarity it swings to full, then if I quickly return it to the original polarity it swings back to zero. Is this normal?
My fuel tank is roughly 2/3 full. I don't know if I'm doing this correctly, but measuring the ohms between the yellow/brown wires at the gauge end, with the gauge unplugged and ignition on, gives me infinite resistance (OL). With the fuel gauge fitted and ignition on, I have 12.2 volts at the green/black wire and just over 7 volts at the yellow.
Do you think the problem lies with the sender, or with the gauge itself? Thank you for any input.
The gauge is apparently not working on the bike. On the bench, when I connect a 9v battery across the terminals, positive to green/black, negative to brown, the gauge does not read. (The following will show it's actually trying to go backwards). If I then reverse the polarity it swings to full, then if I quickly return it to the original polarity it swings back to zero. Is this normal?
My fuel tank is roughly 2/3 full. I don't know if I'm doing this correctly, but measuring the ohms between the yellow/brown wires at the gauge end, with the gauge unplugged and ignition on, gives me infinite resistance (OL). With the fuel gauge fitted and ignition on, I have 12.2 volts at the green/black wire and just over 7 volts at the yellow.
Do you think the problem lies with the sender, or with the gauge itself? Thank you for any input.
Last edited by Howard64180 on Sat Aug 22, 2015 7:51 pm; edited 1 time in total