Fuel Gauge doesnt work

I bought the car used it's a 93 escort and well the gauge always says full. I was wondering what i can do to fix it, do i have to get under the rear sit and look at the sender unit?

I have a 1991 mercury tracer and it had the same problem, except it worked a little. It wasn't accurate at all. The sending unit had a recall on the 1991's but I'm not sure about the 1993. I would try getting a sending unit from a car in the auto wreckers. Hope that helps, you might just have a short somewhere though. But you can rule that out after replacing the sending unit.

I have the same problem on my 97 Ford Escort. Can you tell me where the sending unit is located and how to replace it?