Batteries not recieving voltage from Alternator

Did you check the voltage at the alternator as several have suggested? If you had sparks coming from any wires or cables when changing the starter you probably blew a fuse.
On a 2017 Kenworth W900, the alternator fuse is located in the power distribution box under the hood on the driver's side.

• Check the fuses: While the main charging circuit is a breaker, smaller fuses in the same box protect other parts of the charging system, such as the voltage sensing wire. Use a multimeter to test for continuity on all fuses and breakers related to the charging system.

 

How to spot a failing heavy-duty alternator | Commercial Carrier Journal
I didn't read the article.