Use sum(Throttle) * 1
1 is the speed at which the rotator will spin. Set it Lower for higher speed higher for lower speed. You can add damperMultiplier to the joint Rotator section and set it to something like 10000. Tweak this number to fit your need.
Is it an AEWAC that you are making?

Simplest solution:
Set the max of the rotator's inputController to 1E+15 and have it be perpetually active with Activate8 assuming you don't have that AG set to something else.
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And make the rotator either really heavy or have a really slow rotation speed to mitigate the tilt caused by spin.

@SILVERPANZER doesn't work it acts like free spin also, I want it to have an input like throttle to make it spin. Thx for the help tho

sum(X)

X - The speed at which you want the rotator to spin.

or

sum(clamp01(Act))

Act - Rotating Activation.