Hi All

Over the weekend, we had to drive through a lot of rain and 4 inches of surface water on the roads. At the time, the car was fine, onto Sunday and when I started it up to go and get fuel the battery icon appeared on the dash. My immediate thought was alternator so I had a mobile mechanic visit and fit a new unit. Unfortunately the first unit didn't appear to provide over 13.5v at idle and the icon still appeared. Fast forward to today, and the chap has fitted another unit and although the voltage is around 13.7 onwards - the icon still remains. 

I'm wondering if there's a possible water ingress issue somewhere? The powertrain control module fuse (7.5a) had blown and this has been replaced, there are no current errors showing on the diagnostic equipment. Could there be anything else? The mechanic has given up and suggested getting an auto electrician involved, 

Forgot to add - it's a Ford Grand CMax 1.6tdci (second gen) 

The original alternator is back on and putting out 13.5 - 14.5 volts now. Battery is receiving a current as normal but not idea what's happened!