Fuel gauge only going to 3/4 when grounded?

Thanks, Del, for giving me a few more directions to look. Last time I had the board out (a couple months ago to replace the speedo, needle broke), I refastened a few loose pins for the plug, and did a continuity test on everything I could. I only had to solder up a couple spots, everything else seemed fine. I just went out to the shop and checked the other 2 dash gauges, they both swung to 3/4 of their travel when grounded. Now, the oil psi gauge goes full tilt when the key is on (wire disconnected), but I always thought that was normal? I've got a charger hooked up to the battery, voltage is 13.3 key off, 12.9-13.1 key on. I'll start with putting a good ground wire the board tomorrow.