Originally Posted by daddygo:
You guys will like this one.... I too had the gauge stick on full then drop to about 3/4 way, then drop to empty even though the tank was half full.
Took the gauge to PA Speedo and they said it registers right. They suggested changing the fuel sender.
So I did. NOW my gauge reads 2/2 when full and as I use up the fuel the gauge rises until it pegs it at 4/4 with half a tank left. There are only two wires and the ground has a circular connector versus the sender's tab connector. Didn't mix them up.
I do use the trip gauge, but got a surprise when the jets were changed on my carbs and the mileage dropped. Had to readjust my calculations.
Then you got the wrong sender for your gauge. The Ohms range for the sender has to match the gauge's expected range or it won't read right (including only half-range and backwards like yours). Your gauge could be 0-30 ohm (empty-full), 10-70, 73-10, 0-90, 90-0, 10-180, 240-33, etc. Find out and buy the sender to match.
The reading not being linear is a consequence of the tank shape and float design not matching well. For example, the superbeetle sender has 2 floats on different length arms both actuating the same rheostat to account for the change in tank cross section as the fuel level drops.
