[Jbuchsdvm]

Fuel gauge is not reading correctly. Upon troubleshooting I pulled the fuel sending unit from the tank. I tested it with an multimeter. The ohm readings were backwards. When float was down (empty) it read 10ohms and when it was up(full) it read 180 ohms. This totally opposite to what I expected or assume it should have read. Any thoughts?

[jclark003]

Most marine fuel tank senders are 33-240 ohm where 240 is empty. There are senders out there that are reverse (low ohm, low tank). I think VDO has a 10/180 ohm tank sender in which the 10 is empty. They have a matching gauge for that ohm range.

All the Tiara's I have owned had WEMA 33-240 senders. might be worth pulling the sender from your other tank and checking the impedance range. Or if you can pull a part number from the gauge or the sender you may be able to lookup the range through the manufacturer.