Tamper with equipment (3)
I believe the answer is:
rig
This clue is a double definition.
'tamper with' is the first definition.
(I've seen this in another clue)
'equipment' is the second definition.
(rig is a kind of equipment)
(Other definitions for rig that I've seen before include "Oil-drilling device" , "uniform perhaps" , "Apparatus; outfit" , "Provide with clothes - for oil well?" , "engineer or > doctor" .)