Another fuel gauge question

97 300 tdi disco 1 - Refitted tank and new fuel sender. Gauge works on dash and is showing quarter full - about right for what i tipped in. Before I started the project (welding chasis), when the engine was off, keys out, fuel gauge used to go to zero.
Now it continues to show the tank level. Is this normal or wrong? And as it is showing the correct reading with the engine off, is it pulling power from the battery to do this (bit worried this along with the alarm will drain battery).

New boot floor not yet in so have easy access at the mo !

thanks guys (and girls!).

i have a 94 300tdi & according to the hand book (which i was lucky enough to find in the glove box) the fuel gauge does read the fuel level in the tank even when the key is out.

My 95 300 TDi reads the level with the key out, drops considerably when the engine is running...

94 300tdi, fuel guage drops to zero when ignition off. Now I wonder if mines duffed.....

Thanks for the feedback. Will leave things as they are and get the floor down.