Have a '49 3100 6v. When a 30 ohm sending unit is installed, the needle on the gauge only moves about the width of the needle near the empty hash mark when the float arm is operated from stop to stop. When hooking up a 240 ohm unit, the needle operates accurately but in the opposite direction. Float up, needle down; float down, needle up. At the half way spot, needle reads half full. Gauge is original.
Can I switch the leads on the back of the gauge without damaging the gauge? Or, could I use a Ford product as I believe they are wired opposite from GM products. In other words, grounding the gauge wire at the sending unit will peg the gauge full on one make (can't remember which) but peg the gauge empty on the other make. Hope someone can help.
Dave
