1999, ox66, 225hp: which wires to check TPS?

a couple questions:

from the service manual it says set the meter to read dc voltage to the pink and orange wires of the jumper test harness....

- does this mean connect ground from the meter to one of these wires and positive from the meter to the other wire....or does it mean connect the ground from the meter to the engine block and test each of these wires separately, and hopefully get the same reading..

- also, if the sync is all done first, why do you disconnect the throttle link from the throttle valve for number one throttle body before testing the voltage...is it just to make certain the valves are all fully closed if for some reason the sync was not done properly

thanks.

[boats.net]

Connect one meter lead to each of wires to read voltage between pink and orange wire. The TPS is to be set with throttle plates completely closed.