Ignition switch fuse blows as soon as engine starts

I just had a rack and pinion put on and while the mechanic was doing the alignment it failed to start after. He found three bad wires and replaced them. (Tiger wire on the starter, starter power wire from battery, crank sensor ). It’s been fine for a week and suddenly stalled on me two days ago. He told me to check ignition switch fuse and it was blown. I put a new one in, started the van it ran for twenty seconds and stalled. Any idea