Clutch: Mechanical friction device that engages or disengages the engine from the transmission.
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It is located between the engine and the gearbox. It is used to disengage the engine, which prevents the movement to be transmitted to the gearbox while the gear shifts are made. Roughly speaking, it is the piece that disengages the engine from the wheels when the driver presses on the clutch pedal.
With 70 PSI in system (injected air through gauges ) turned on AC and clutch didn’t engage. I can’t find fuse box illustration to tell what fuses or relay to check.