B737-800
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; Flight Crew Rejected Takeoff
Human Factors; Aircraft
During the takeoff roll at about 70 knots; the left Flight Control Low Pressure and Feel Differential lights illuminated. I elected to reject the takeoff. We cleared the runway and ran the QRH for the lights. I discovered that the Left Flight Control Guard switch was not fully down. I closed the guard; and system reset. We evaluated the brake cooling. No wait time required. We were still above the minimum takeoff fuel; and taxied back for takeoff. I did advise the passengers for the reason for the reject and also advised that the problem was fixed. The threat is that a guard switch; that might look fully down; could in fact jar loose on the takeoff roll.
Boeing 737-800 Captain reported executing a rejected takeoff due to a Low Pressure and Feel Differential lights becoming illuminated.