Big dog
Even people that are factory trained still get caught out with problems the only difference is a dealer can throw parts at the problem to solve it and return the parts they dont need were a self employed guy cant thats the difference
Trucks are getting that complictated factory trained engineers is not enough most big dealers have there own technical staff to help engineers were self employed guys dont have that luxury.
Even if you work for a dealer you have the same problem to when it comes to working on different brands.