sry, taking a closer look, id say that IC B may be wired wrong and that ICC pin13 should be disconnected from R5 an rewired to the other end (ICB pin5) ...this is just a rookie guess...
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also i question that whole schematic by the look of the ICC and ICD id wonder if they are just switching on and off without speed control.....try this circuit i designed 4u.... although R4 & R5 values need to be adjusted for sensitivity selection, and R1 & R7 are valued for your on off limits, it should work OK,,
....maybe wait for someone else to OK it for us before you go ahead with it!!!