I have the schematic. Both X and V cause the motor to turn. As shown in prior excerpts, AA is held on whenever either red and green (right side) or yellow and purple (left side) bumpers are lit together. When AA is on, the kicking rubbers are lit to score 10, which is a helpful clue.

To refine what TimMe said, the V relay is used to move the arrow stepper ahead at the start of a game, if the game is on 3-ball. I presume it would be deemed too hard to earn 13 steps in 3 balls. You've used it to prove that the Arrow Unit can step up, but that is its entire diagnostic value. However, I see it as sending all five Motor 1A pulses through to step the arrow 5 steps.

I looked at all the switches on AA (5A, 1C), and the one TimMe called attention to is the only one that has any chance of affecting the Arrow Unit. Three of the switches on AA are devoted to lighting whichever hole also has its 100 point (red) light lit.

Q is the conventional 100 point relay (always L in later games), while X is the "100 point hole relay" (and Y and Z do the 200 and 300 for the holes). The only other way to actuate Q is by carry-over from the 10s. There are no 100-point targets on the field.

The X, Y, and Z switches leading to the Q coil are how the holes score 100, 200, and 300, respectively. When you follow TimMe's yellow line starting from the right, you go through the masking switches and end up with a pulse headed for two different switches on X. If the hole with the red light gives 100 points, then we can say that the pulse made it that far. You will need to test each of the holes individually to see that each one gives 100, 200, AND 300 when the respective lights are lit.

If each hole gives 100, and if the kicking rubber lights come on when they are supposed to, then the issue is isolated to the AA and X switches on the yellow path. I think you should put the game on 5-ball to test further, so that V is not adding complications. It's possible that the Arrow Unit is not stepping and/or resetting properly.
.................David Marston

To clarify: you're saying that any one of the three holes, when lit for 200, is scoring only 100? But any one of the 3 holes, when lit for 300, is scoring the full 300? You can rotate the hole scores by cycling the motor, such as by scoring 50 points. It would be easier to believe that a specific hole is scoring badly than to believe that ANY one of the holes fails for 200 but succeeds for 100.
.................David Marston

I suggest that before you do the TimMe advanced diagnostic, that you absolutely confirm that each of the 3 holes correctly scores 300 points when it is lit to do so. That confirmation will exonerate the proverbial yellow path going from the right "rail" to the Motor 3B switch that is the suspect.

For more fun, you can set the Arrow Replay Adjustment to 2 and see if you get 2 replays at the appropriate time.
.................David Marston

On topics you started, the cluster of option buttons (usually at the top right, but I don't know what device you're using) for the topic includes an extra one with a check-mark icon. You can use that to call it resolved. The information will remain for future owners of Lite-A-Card to find when they have issues.

BTW, where are you located, geographically? Is there any chance you would bring this game to a show for us to play and admire?
.................David Marston