Thanks for all the comments so far. We have found out that the pump is drawing to much current, its ment to draw 16amps, when the Fiat garage tested it it drew 27amps. It normally has a 30Amp fuse on it however the AA fitted a 60A fuse, this has been working fine but the garage didnt like it much..... I tried to fit a 40Amp fuse but this blew within 1 mile!! As the pump is a unit in itself it need to be replaced, we have been unable to find any other garage apart from a main Fiat one that is able to quote for the job!!