The fuel gauge on my 73 century suddenly malfunctioned today when I turned on the ignition. It was reading fine yesterday. The needle is stuck well past the full mark with the ignition on, and takes half and hour to return to the original position (in this case, 3/4, which is approximately the current level in the tank). From looking at other posts, assume this is likely a bad connection at the sending unit? To access the tan wire described for testing, requires removal of the spare tire and trunk mat? Thanks.
Check for an intermittent ground wire connection from the sending unit to the frame or perhaps to the bumper.
I have disconnected the ground wire from the tank to the frame, cleaned and reinstalled. I also disconnected the connector from the tan wire to the tan and white striped wire in the back of the trunk and grounded the connector on the tan and white striped wire going to the tank to a ground wire on the trunk latch. According to an earlier post by Cazbah 362 regarding this issue, Buick 64203 said that this should cause the gauge to go to empty if all is well forward from the tank. Gauge still shows over full (over temp light) so it's likely the gauge itself is the culprit?
"Duh" moment. Grounded tan wire from gauge and gauge went to empty, so all is well it seems with the gauge and wiring to trunk. Leaves sending unit or connection/ground to it at this point. Will need to get tank down when it has less fuel in it for a closer look.
