The center diff lock does not lock the rear or front diff’s.
A full time four wheel drive vehicle has traction dependant, power transfer to both front and rear axles through the center diff, i.e. if traction is lost on the front wheels, all the power will be transferred to them as the point of least resistance.
To prevent this you engage the center diff lock.
The center diff lock equalizes the front and rear diff’s in a 50/50 split, thus ensuring power distribution to both axles.
As a safety feature due to improved traction, engage center diff lock on slippery and loose surfaces. Be aware that steering is harder due to the different tracking between the two axles in cornering.
Engaging the center diff lock on firm terrain, could cause torque wind up, as there is no slippage.
To release torque wind up, reverse and go forward in a straight line repeatedly until the indicator light goes off.