I am having pretty much the same problem, the sending unit I bought said 6 or 12 volt, 0-30 ohms. The sending unit was universal and it came with a chart. The tank behind my seat in my 53, 3100 is 12 inches high. The chart shows where to adjust the up and down arm travel at 6 1/8 inches and the length of the float arm 7 9/16 inches. If I lay the sending unit on the bench and measure the tavel from top to bottom of the float at this adjustment it gives me 11 inches travel. I figure about right for a 12 inch tank. I think I did that part right. Just for the hell of it I put my ohm meter on it and put the positive lead on the sending unit wire screw. I touched the negative lead to the top of the sending unit one of the screw holes that go into the gas tank. The ohm meter goes up and reads, to me that is counter intituive. Doesn't the center screw that is insulated from the rest of the sending unit and the wire running down to the reastat sound like it is grounded? Shouldn't I have gotten no reading at all? Is it shorted out? This is the second sending unit I bought and I think my thinking is backwards. Does Denny still stop in to read these boards everyonce in a while? He has slapped me around before and showed me where my thinking was flawed, not that anyone else can't tell me how stupid I am, I am always open to that. OK, well I won't install it quite yet and see if I get an answer from someone that will tell me everything is OK (hopefully). I bought a new sending unit and a new 6 volt gauge. Thanks John
