I HAVE A 1987 CHEVY MONTE CARLO LS. RECENTLY IT CUTS OFF WHEN I TURN A CORNER AND WHEN I BACK UP TO PARK. IT DOES NOT SHOW ANY TROUBLE CODES. I CHANGE THE SPARK PLUGS AND CHECKED THE VACCUMS HOSES. WHEN I,M ON THE HIGHWAY,IT DOESN'T SHUT OFF.HAS SOMEBODY HAS THIS PROBLEM BEFORE............

 

Check your lead going from the alt to batery, my old blazer had this kind of issue ended up being a bad conection between the two

 

What year was your blazer?

 

89 it was a s10 blazer 2.8 v6 but had the same kind of deal dying randomly, which in a sence is wierd becuase it should run off the bat for a while but mine just died, random bumps, turns ect would triger it

 

Also might want to check the conections at the starter, there should be 3 conections on it, the battery, start and run, the run wire might be loose or coroded, also check any grounds a lose/corroded ground can cause funky issues too!