usually under the the drivers side rear passenger seat, lift off a large black plastic cover and underneath you shall have your fuel gauge sender unit + pump if it's a petrol.
check ground on fuel tank
I'm guessing you mean when the tank is full. It is probably the fuel sensor.
A gauge for measuring fuel in a tank.
beside the fuel tank
check for obstructions in tank interfering with sending unit
Tank capacity is 45 litres of fuel.
In the tank
all peugeot 205's have a fuel capacitie of 50 litres
in the tank
The fuel gauge sending unit would be found inside the fuel tank.
You may have a faulty fuel gauge sending unit in the fuel tank.
Whether or not a march fuel gauge will fit a B13 tank depends on the size of the march gauge. You should be able to find a march gauge that will fit on a B13 tank.