I just picked up my 98 blazer from a shop that did a lot of tune up work for my truck. plugs,wires,cap & rotor button ,belts, hoses, new radiator, frt brakes & rotors...etc..

On the way home, I notice that my engine light is on. Could have something got bumped that cause this?

 

Yup, could very well have been. Take it back and have them check it.