I have a 91 Four Winns 18.5 with a 4.3 engine. Last fall, I noticed that the wood above the gas tank was soft. This winter, I removed the gas tank and replaced the wood and figerglass around the gas tank. Everything went well. I was able to improve the reinforcement in the gas tank area. I used 3/4" wood instead of 1/2" and added some additional support. I put everything back together and the boat works great. However, the gas guage will not longer work. When I connect the wires, the gauge goes to full. There are three wires: Green, Black, and Red(or Pink). Right now, I have the red and green wires connected to the sending unit and the black wires connected to a bolt on the sending unit for ground. The gauge reads Full. If I change the wires around, the gauge will read empty. I've tried every combination and get get the gauge to work. Is this a wiring issue or do you think the sending unit may have been damaged when I removed the gas tank? Any other thoughts would be appreciated.