2008 Land Rover Freelander front wipers not working

For two weeks i have had a problem with front wipers not working, rear wiper and all washers work of the same stalk but not the front pair, new motor fitted and relays fitted, tested all fuses and relays and engine module, all good. checked all system with land rover computer, no faults found. Had to get AA out yesterday as they went again two miles from home, he done his checks and we have power from stalk to relays to motors, all showing they are working, his verdict was that from fuse box to wiper motor a wire is shorting itself out or a poor solder connection inside fuse box. Any advice ? Andy