hi all new member here i have a escort van 1.8d 1997 it used to be a fridge van and alternator belt goes round air con pulley aswell but its a new belt i have put on it now a 4pk 223 it was a 4pk225 on there it has been adapted so thats why bigger belt, everything seemed ok but now it makes a noise at high speed sort of a screetch noise but when i put loads of wd40 on it it goes for a while then comes back could it be the air con pulley? please any ideas would be grateful