Fuel Gauge Issue

I bought a X reg 1.7 puma about 6 months ago and I have always had an issue with the gauge not reading correctly.

When first I got the puma petrol gauge has always said I have a full tank which I know it is wrong as I have ran out of petrol a few times now lol.

I have changed the sender for another one but no change. The needles does move as when you turn the car off the needle goes down to empty and as soon as you turn it on it shoots straight up to full. It even moves fine when you do a needle sweep.

A few weeks after changing the sender, I get in the car one morning start it up and while i got myself sorted a heard a loud thud, like something had been dropped on the roof. I jump out look round the car but couldn't see anything so thought nothing of it.

As i am driving the gauge slowly starts falling and stops at half way and stays there for a little while then very slowly creeps up to three quarters!!

After a 30 mile trip i leave it stood for about an hour before the journey home. Start it up and sit on half a tank again. I put £20 worth of petrol in it but the needle does not move.

So now it reads anywhere between half a tank and three quarters but never anymore ore less no matter how much petrol I put in or use.

I have also change the dials about a month ago and still does exactly the same. I have even rewired the gauge a couple of weeks ago and again no change.

I noticed the other day that i had a fuse missing from the fuse box in the engine bay. After checking it is for the EEC module. I fit one and no change to the car in any way.

I am so stumped as to what it could be now.