I think you have two issues.
Paul answered the first, mainly that 12v is not adequate to charge the batteries.
Second issue is you probably fried your controller, or popped the fuse, so now you have zero voltage reaching the batteries. Check the fuse on the wire from controller to batteries. With luck, that is all you need to replace.
You did not mention if the batteries were ever charging with the solar arrangement so we don’t know if the wiring was correct.
Remember, many battery banks are wired both in series (+ to -) and in parallel (+ to +, - to -) so the og wiring you changed could be correct.
A picture of your batteries and the location of the OG solar wires will help greatly.
Larry, Eileen, and Finley
2004 Alpine 36FDDS
Third motor home, first Alpine, no need for another.