Fathers Day Gift - Seafari 20

[jtharmo]

I know I have had my Seafari for well over a month and the weather up here has been near-perfect for boating but we finally got the boat out for the first time this weekend. It was just a quick spin and everything worked except for one thing, the fuel gauge. It is an old Medallion gauge that is original to the boat ('78). Does anyone know what the resistance range is this vintage gauge reads? I checked continuity between the gauge and sending unit, the grounds as well as 12v across the gauge. If I short the gauge it reads full. In practice however it doesn't move. I now the tank was changed by the PO and I assume by the look of it the sending unit was too. I'm also assuming since its newer the sending unit is a 240-ish to 30-ish ohm unit. Since everything seems to check out on there own I'm trying to figure out if this I just a compatible problem.