Wiring for a Mechanical Stop Sign?

[StratoGeezer]

Hi - I've just bought a replacement stop sign mechanism that seems to work just fine when hooked up to power. The problem is I've only got 2 wires protruding from the side of the bus, where what is left of the old (original) mechanism is mounted. In order to install the new stop sign unit, I believe I should have additional wires accessible - to enable the replacement unit to function.

Does anyone have a wiring diagram for a school bus stop sign? Thanks! I'm new to this group - and excited about sharing and gathering expertise!

Thanks!