jom 98 Report post Posted October 21, 2013 My fuel gauge starts off showing the correct level, then will suddenly jump to empty and occasionally then to full. It also returns to the correct level for a bit, before showing empty again. I thought it would be the usual suspect - drivers side fuel sensor - but I've taken that out, looked for broken and cracked wires, checked the resistor surface, run the float over it's operating range and checked the resistance -all OK. Then I did the same checks on the passenger side - also OK. The next step was to replace the instrument cluster (I needed one anyway) and the problem is still there. Any ideas? Jo Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted October 21, 2013 How full & how empty does it show? To extremes? If so- would mean completely open circuit & short circuit. Have you traced the wiring? Hard to imagine a wiring issue causing extremes though Quote Share this post Link to post Share on other sites
jom 98 Report post Posted October 21, 2013 How full & how empty does it show? To extremes? If so- would mean completely open circuit & short circuit. Have you traced the wiring? Hard to imagine a wiring issue causing extremes though Very nearly full, and off the scale empty. I get that empty = short circuit, but I'm mystified by the reading that's fuller than the tank really is - which indicates more resistance. Btw, the drivers side sender (the expensive one with the fuel pump) is only 6 years old. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted October 21, 2013 Very nearly full, and off the scale empty. I get that empty = short circuit, but I'm mystified by the reading that's fuller than the tank really is - which indicates more resistance. Other way around - over full is a short circuit. empty is open Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted October 21, 2013 Edit, you are correct for some older vehicle fuel gauge systems Quote Share this post Link to post Share on other sites
