Do you have the same voltage on the right flipper lugs as the left flipper lugs?

Check your EOS switch on that right flipper???

Does the right flipper work in coil test?

Have you manually tested the coil by grounding it with a test lead? Make sure you ground the center lug.

You have power but no ground. Start tracing the wires back to the switch in the cabinet and the interconnect board. A schematic will be helpful but if I had to wager a guess you have something broken on the lower right flipper EOS switch.

The right flipper on BK2K is double-stacked: the lower flipper activates the upper one when the EOS switch is closed. If I recall correctly this switch switches *power* to the upper flipper and the cabinet switch switches ground but it's been a while since I looked at it.

Flipper can't fire in coil test on a pre-Fliptronics Williams game. It's just a switch. (Okay, the interconnect board has ICs that can tell when the flipper is flipping, so it's possible that there's a problem with that.)