Star Trac Pro S, Pro, Pro Elite Pro STM Treadmill Owner's Manual page 17

Position the bottom of each handrail over its associated mounting hole in the frame assembly. Insert one 5/16" x 7.5" screw,
with a flat washer installed, through the bottom of the frame assembly, and thread into each handrail. Use 9 1/2" wrench
to tighten the screws.
Step 5e
6. Connecting the Display Cables
For units with fans (PRO / PRO ELITE), connect the cables tagged 715-3444 and 715-3419 from the display to connectors
J3A and P4A, respectively, on the 715-3441 PCB in the motor compartment. The display cable connectors are keyed, and
can only be installed in one direction only.
Step 6a
Connect the cable tagged 715-3411 from the display to connector
P3 on the 715-3397 (for 110-volt) or 715-3398 (for 220-volt) PCB in
the motor compartment. The display cable connector is keyed, and
can only be installed in one direction only.
Step 6b
STAR TRAC PRO S / PRO / PRO ELITE TREADMILL O ' M 15
WNER S ANUAL