RV Repair: Fuel gauge doesnt work

Question
We just bought a 1982 Fleetwood Tioga RV with a 350 Chevy motor but didn't realize when we bought it that the fuel gauge didn't work. Its otherwise in good condition and needs only a couple of other minor repairs. Its been years since either my husband or I have done any kind of mechanical work and were wondering how to test to see what the problem is or should we take it in to get this repaired. Could it be a sending unit or just the gauge itself and is there a way to test it to find out? Thank you.

Answer
you should be able to put 12 volts to the back of the gauge and see if it moves check all the fuses. I would be that the sending unit in the tank has gone bad  based on the age of the unit. Chevy made a replacement for this at one time. If not a universal unit will fit you may have to make some adjustment. Fuel tanks are heavy its probably best to send it to a shop. You might send the vin and I see if i can get a breakdown of that unit

Thanks and good luck