Problem with losing power

[jashley]

My girlfiend has a 02 Clio 1.2

For the last few weeks a few times she has been driving along and the electrical light comes on and she loses some power and the car seems to drag, not all power is lost..

She seems to think now thats its if its raining or beening raining..Or after she has driven though a puddle.....

Is there anything i can check/look at/do....before i take it off to the garage....

Any help welcome please

thanks