Bally Free Play
There is only one switch that controls free play on a Bally game. Set the credit wheel to zero credits (shows zero credits through the backglass). On the stepper unit there will be a knotched wheel with a fixed pin sticking out. This pin should have opened a switch only when the credit wheel is at zero credits. Adjust this switch so it is permanently closed (or use a jumper wire), regardless of the credit wheel position. Note there may be a second movable pin (with a slotted head). This is the maximum credits pin. Do not change the switch this pin contacts. Your Bally game is now set on free play.
Bally credit wheel: adjust one switch permanently closed when credit unit is at
"zero" credits for free play (right red arrow). The blue arrow (left) is the max
credit switch, which should be normally closed (otherwise the game will not add
any more credits).