Problem Corrected:
I have been able to figure out the wirings and have corrected them. For Reference, if member is facing a similar issue then this thread will help him. Red wire goes to the ignition and is responsible for powering the rotor and turning it on once ignition switch is turned on. Yellow goes to the warning lamp and Black/Red wire is reference Voltage and should be connected with battery through ALT-S fuse.
Follow Ups for those who may need some Help
Unfortunately, we went into further diagnosing the issue and realized that reference wire(Red/Black) in no way was connected with ALT-S fuse by factory. 5 AMP fuse was a dummy fuse doing nothing where as reference wire was going inside the cabin Area through factory fitted Loom and connection was being taken from positive wire inside the cabin area and that connection was broken somehow. Reference wire was cut in between from loom, brought back into fuse-box and connection was restored with the ALT-S fuse and battery as it supposes to be on wiring diagrams.
Results
Voltage on terminals can be seen between 13.8 to 13.9 Volts with no load and full load condition.
Question from Expert: How can I increase the output from Alternator and set it 14.4 Volts instead of 13.9 Volts currently???
I intend to drop 0.6 Volts from Voltage Regulators reference wire (Red/Black) and fool the regulator. Will this work???