i have a 1995 blazer i changed my thermostat now i get a s.e.s light and it is running rough and die's when it comes to a stop also i have an obd1 system how do i get the code.

 

The '95 is actually a mix of OBD1 and OBD2 often requiring a special scan tool to read the codes. Most Autozone and Advanced Auto stores now carry the appropriate scan tool and can read the codes for free.

With the resent work that was performed, have you gone through and checked to make sure that all of the electrical connections are properly connected and that nothing has been left loose or undone?