Absolutely. The way this circuit works the 18OR line gets energized at the relay to pull the arm over placing 12 VDC directly to the motor via the 12OR wire. You could simply run a 12 VDC jumper from the battery to the relay post holding the 18 OR wire. Word of caution, anytime you lift wires or land jumpers you can F things up real bad, real fast. Be careful. If unsure place a 15 Amp fuse inline with the proposed jumper beforehand. Anyways, you should hear the relay click as it repositions.

If I was a betting man I would guess your problem is with the switch holding the 14BRN and 16Y mounted in the control panel.