Car wont start imobiliser light flashing eratically getting codes D147 D900 E510 any help would be appreciated

I'm assuming you've got these using the dash trick? They're pretty useless codes either way. You need to use the obd2 port and preferably forscan on a laptop.

Yeah did the dash trick im getting engine malfunction light also. I was having a battery draining issue to start with so took it to an auto spark. He said the aux heater was done but still drawing power to it so he took fuse out under bonnet ( one that has bolts on it ) next day car wouldnt start then left it 10 mins it started but day after wouldnt start then engine and transmission light came up on dash. So did the dash trick today then i seen a video on how to reset engine malfunction light did that nothing happened tho so now im left with eratic flashing imoboliser light and engine malfunction light and car wont start. 

Don’t know if cmax has same common problem as focus, on focus of that era the problem you have is usually (not 100% always) caused by cracked soldering in the instrument cluster on the connector socket pins(16 pins I think) dismantling the cluster to get the circuit board out and resoldering the pins usually fixes it.  More of a job for an electronics person than a car mechanic , videos of this work on youtube

Ive just took clocks out have them took apart. Now down to circuit board time to get it under the microscope fingers crossed ive cracks in the solder because this car is driving me mad