I have 2002 3800 Open(dual tanks and guages) My port gauge is working but my starboard gauge stops at 3/4 tank and will not go lower. When I fill the tank, it does go back to full but when it reaches 3/4 it stops. Any insights as to what could cause this and if there is a fix are appreciated.
I posted a reply a few days ago on how to troubleshoot a fuel gauge, you might want to go look at it.
To test the fuel gauge, disconnect the pink wire (sender). Turn on your ignition switch. The gauge should read empty. Ground the pole where the pink wire went to the black wire and it should read full. If both of those are true, your gauge is fine. Reconnect the pink wire. You then need to check at the sending unit. Disconnect the pink wire and ground it out. If that works you have a bad sending unit. If it doesn't work you have a wiring issue.