MacDon FFT FD75 Assembly Instructions Manual page 228

2. Check that float lock linkage is on down stops
(washer [A] and nut [B] cannot be moved) at both
locations.
NOTE:
If header is not on down stops during next two steps,
voltage may go out of range during operation causing a
malfunction of auto header height control (AHHC)
system.
3. Adjust cable take-up bracket (B) (if necessary) until
pointer (A) on float indicator is on 0.
4. Press CALIBRATION icon (A) on main page of combine
display. The CALIBRATION page appears.
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SETTING UP AUTO HEADER HEIGHT CONTROL
Figure 5.165: Float Lock
Figure 5.166: Float Indicator Box (Most
Common 5 Volt AHHC Sensor
Assembly Shown)
Figure 5.167: John Deere Combine Display
218
Revision A