Real simply. The center post on the sender is not a power supply. It's a ground supply. The sender just supplies more or less ground to your gauge, according to how much gas is in the tank.
57 GMC LCF 370 55 John Deere 40-W 59 John Deere 430-W 2000 GMC 4x4 56 John Deere 420-W Pix on Photobucket
