My car is Ford Focus 1.6 2003 zetec petrol.

Hey guys I really hope someone with more of a clue can help me.. in a nutshell,

I was driving in the pouring rain for the first time, not long after I saw water coming through the window into my passenger side footwell, next time I start the car the air con has gone dead not sure if it’s related.. but then that night I go to start the car and the battery is flat.

 

we jump start it and it runs fine idiling for 15 or so minuets before it cuts out, then again idiling for 5 or so minuets before it cuts out which next it just won’t restart.. 

my friend let me use his computer which gave us only the error code P0232 fuel pump secondary circuit high.. his manager advised him who adviced me it probably needs a new fuel pump..

I bought a new fuel pump and fuel filter and fitted them with my friends help.. we swapped the relay with the highbeams relay and the highbeams seem to work fine so I’m not sure if the relay had issues..

however now the car still won’t start and it still has this error.. any suggestions what it could be or where to start?

also I noticed yesterday the ground for the battery and something else close to it, maybe the PCM both have rusted ground points with blue copper on the ends of the cables not sure if this would be any interest thanks so much for any advice in advance 

https://www.yourmechanic.com/article/p0232-obd-ii-trouble-code-fuel-pump-secondary-circuit-high-by-jay-safford

https://www.obd-codes.com/p0232

https://www.autocodes.com/p0232_ford.html

http://www.automotivetroubleshootingsecrets.com/P0232_OBD2_fault_codes_8.html

Thanks for the reply I have read all of these websites but I’m still a novice and am unsure. 
should I use a multimeter to check connections between pcm, battery and fuel pump? Should I assume it is an electrical fault as I’ve swapped the fuel pump with no results? I can hear the fuel pump prime which is the strangest part