As a last resort you could do some reverse-engineering and if you can identify the IC's, then obtain their normal voltage from a Spec sheet, by resistance check from IC power and common, the power leads can be identified, quite possible black and red are power, with green,white,yellow the ABZ outputs, as long as it is not a serial output type.
The ABZ can be identified with a simple voltmeter method, turning the shaft as slow as possible.
Al.