That switch is activated at 84" of lift. Connect a DVOM to CA102-2 on the access 4. Attach the other end to CA101-7. There should be 22-26v with the platform fully lowered. If the voltages are not correct test from the key switch to CA102-2.
If you are getting the correct voltages then it could be the access 4.
These test have to be performed with the lift on, both foot pedal pushed, gates closed, and hands on the hand grips.
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