2004 Renault Megane

Hello from Spain as you know we really do not get to much rain here My Megan 1.9 dci has beena good old girl Hmm untill the front headlamp bulb went took the round cover off under front wing pulled and out it come with spring Garage wanted 40 Euro to replace so wedged in tillafter Xmas BUT forgot to replace cover under wing. It rained bad lots of larger than normal puddles couple of lights came on dash then stopped with all lights flashing on and off on dash headlights flashing on and off wipers same. Left for a while returned car started got me near home with all dash lights on and off then would not start. Again left overnight and started ran for 5 mins then same Has happend (these cars do not like water) Tried to locate breakdown view of vechicle on web but not found much. Please may I ask were should I start to look. Thanks John Spain Cant donate at present as in internet cafe.