caspermutt

Hello everyone Im a new owner of a galaxy 2.3 1998 ghia Ive only had it a week and Im into it all ready, the problem is that it has stopped charging the battery, Ive had two batteries on the car and the problem is still there, If I put my multimetre from the alt to the earth on the battery it reads 18 volts a bit high I know but when I put the metre across the battery I get 12 volts and it isent charging, I am going to clean the cable joint at the starter and clean up the earth. has anyone any ideas what could be the problem, I hope to god that its not the alt as it looks a barrel of fun to get it off. thanks for looking :(