Quoted from coz6:
I am an idiot yes yes I have never once loaded it and was like wonder how that works all these people talking about loading the arrow I can't seem to figure it out
First go into test menu and coil test. Near the end of list is one for windlance (arrow). Set it to run and pull out white coin door interlock switch, and you should see the arrow diverter working. Might not be running full power but arm should poke through two bottom rails. If it is blocked, loosen screw on top holding it, twist to find sweet spot and tighten in place.
Then during game mode you'll eventually notice the load arrow insert lit solid purple. Send a ball up the right ramp and it should be diverted. (Oh, first use ring button to turn off lock light. This should work when ramp is unlit or maybe with mode light on, not sure about lock light on). Give it a try and report back.
The wndlance/arrow adds a ton to the game and its ingenuity is under appreciated. Sometimes it serves as a skill shot to MAN targets, some of the modes use the arrow feature, and then of course it is needed to kill Smaug. Mmmmphhh yeah, you might to take a look at yours.