You might get the battery checked if the amp meter now reads charging all the time. If its a short charge then settles down, that OK, you just don't want it charging all the time. A bad cell can cause it to over charge.
Its pretty common go from battery ( negative ) to frame, then frame to engine, then engine to cab. What you don't want is to run the ground to the cab and have the starter pull all its power through the sheet metal of the cab. It's better to use a heavy ground like the frame of dedicated cable for the starter ground source.
Sounds like you got pretty well sorted out, just keep an eye on the amp gauge and make sure it settles in the middle once on your way.
