escort 1998 zetec starting problems?

i have the above car and was driving it today when it kept trying to cut out or a sort or misfire,i checked plugs and leads they were ok,i took the fusebox out and put the hairdryer on it and incase it was wet as they are prone to this i then replaced the fusebox and now the cars just completely dead i turn the key and the dash lights come on but thats it,but theres a strange sort of humming noise coming from under the bonnet right under the windscreen i took out the key and the noise was still there and the small red light by the clock on the dash is flashing in different sequences the strange noise has now killed the battery so dont know whats happend help??????????