FORD FIESTA MK6 Can’t get to start

Hello, I’ve resorted to here as I’m simple at my ends with this car I currently am looking at. It’s a Ford Fiesta MK6 1.4 TDI 2006 Reg. There seems to be many different things going wrong electronically. When starting the car, the car makes one loud clonk and then all the electrics in the car start flashing and “spazzing” out. (It’s not the starter motor, new one was fitted about a month ago) When the key is put in the ignition it can start to freak out locking and unlocking doors and flashing the dash lights. Especially the immobiliser (The master key and electric fob key have both been tried) There was a weird fix yesterday, doing a plethora of different things at once so hard to say what, however disconnecting and reconnecting the battery several times and it randomly started! Fantastic, took it back, after running it on and off repeatedly, taking for a test drive, it ran perfect. About 7 hours later, stopped working again and back to spazzing out the electrics... I went to the car and disconnecting the battery and it worked again. Got it back to mine, this morning first time start fantastic. Thought okay something simple, I’ll clean the battery connectors, cleaned them all up and it’s back to doing it again. This time it’s very strange, sometimes nothing at all. Sometimes a big clunk and the weirdest one of them all, I was just sat in the car (doing nothing) key in ignition set to turn one. And I just randomly put my foot on the clutch and all the lights come on... now currently on the dash all I have is the oil lights (oil levels are fine) and a stupidly fast flicking immobiliser lights. It won’t stop flashing/ clicking unless disconnected and re connected. 
The battery is new (ish) about 5 months old according to the previous mechanic 

Stator motor is new as well. 
any ideas? Anyone haha or have I got a haunted car on my hands! 
 

Thanks in advance