Ford Ka 54plate 1.3 petrol?

I was told by an auto electrician that my ka needs a new ecu and probably new loom due to the common fault of water ingress which gets into the ecu and corrodes the terminals. I have checked the outside of the ecu but there is no sign there of water damage although no yet removed the back of the ecu which is only way I can see of access to screw holding terninal block

The problems started with wipers going fast then slow, headlights going bright then dim, all dashoard lights coming on and engine cutting out