23 is typically a wire going to a 20 or 50 pay trace.
bally was generally pretty consistent with:
13 - 2 trace
15 - 5 trace
27 - 10 trace
41 - 14 trace
51 - 18 trace
23 - 20 trace
then 43, 81 and 54. However, when you get above the 10 trace, there's lots of "don't wanna follow the rules" wiring ... sometimes it's due to more/oddball pays, other times ya gotta wonder if they just wanted to use wire colors they had a lot of :-)
your game may not have the 23 wire connected to the payout counter disc because the particular machine didn't use that pay amount, but the wire will be tucked into the bundle unused.