Oldsmobile Bravada no start issue

I just got off duty(military) to find out that my nephews bravada won't start for him, I checked the battery(its good) the issue is when he goes to turn the key there is nothing that happens at all, no noise whatsoever no click no engine turning. Nothing all the dash lights come on like the should etc it just seems like there is no current going to the starter, I am thinking it might be the relay switch?( Not sure if thats the proper name) but the block located on the firewall where there are wires that are bolted to it, one leading down to the stater etc. Any input would be greatly apreciated, thank you in advance!