Sorting thru the many electrical problems are challenging to say the least but I'm getting things working. My gas gauge hasn't worked since I purchased the car last November. (always reads empty) Reading thru the threads, I performed the ground test at the sender. The first test was with the purple wire, power on, and gas gauge went right to full. I turned power off it stood there at full. Lightly tapped the top of the instrument pod a couple of times gauge went back to empty. Grounded it again went back to full. Stood there tapped it again went back to empty. Grounded the white / black wire no low fuel light in the instrument cluster. Do I need a new sender or a new gas gauge or both? Any suggestions or further troubleshooting would be well appreiated.