automatic stalls then starts byself while driving

okay let me start at the begginging i had a new motor put in a 95 2 door 4wd blazer auto. while that was done i had tranny service gear oil changed etcc...now in those 2500 miles i have had my car stall 3 times and start back up before i could change lanes to get off road... 1st time was at 65-70 mph appx a week ago 2 times today 1st at 31mph 2nd time at 45 mph 5 hours apart oddly this stalling and restart happens withen 2 sec. before i can change lanes so WHAT THE HELL IS GOING ON i had the codes ran and there are no codes ....oh and i know my altanter bearings are going bad cuz under load they grind however its not under load when this happens ......i feel like buying a 12 gauge shotgun to feed my car with....help me before i go instane..

Try changing your alternator, and there's a good chance that your problem will go away. If it doesn't it'll be a wire, check the engine ground first