Renault Kangoo engine does not start

Hi, I have a Kangoo 1.9 diesel and I worn the base of the alternator, because a mechanic is forgotten to press the screw of the base and the roller where the strap goes did not have parallel to the other rollers and the belt brother me and I have welded it with aluminum always disconnecting the battery cables, at the end I connect the battery cables and the flashes. Starting works but the engine does not end and there is a red light on the fixed panel, two mechanics an attempt to connect with the switchboard with a diagnostic machine and there is no communication.