Soon after I bought that Residency, the gas gauge quit working. I tried watching the miles and mpg to figure out when I needed to gas up again. Finally figured it was time to fix it. Brought it home to St Louis from Council Bluffs, IA figuring the tank would be pretty low. Dropped the whole tank and pulled the sending unit which I was sure was bad. It took many attempts to figure out what the ohms should be empty and full but I finally found them and the sending unit tested good. I determined the wiring had an open between the tank and a connector near the rear of the transmission so I bypassed the old wiring with new. With the gas gauge again working, I put everything back together - job finished.
When I tried starting the engine with no luck I found out I didn't have any fuel pressure from the pump - so I added about 10 gallons of gas. Still wouldn't start and no fuel pressure! I reluctantly dropped the tank again and pulled out the sending unit/fuel pump. I though it would be a good idea to take the pump with me to match it up with a replacement. I couldn't get the push-on terminal loose. It had corroded and got warm enough to melt the plastic shield on the connector. I had the feeling I was driving TWA Flight 800! I managed to get the connector apart using brute force. I cleaned up the male side of the connector on the pump itself and cut the bad connector off so I could crimp new ones on - (they're only 1/4" spades). Put everything back together and raised the tank again. That was 10 years ago and it's still working. I'm still glade it acted up in my own driveway and not out on the road. I'd read several stories about dropping the tank to change the fuel pump costing around $800.
When the gas line to the generator proved to be leaking, I cut a hole in the compartment above the tank - much easier but a little tight in there for me.