To Set A Higher Set Speed - Ford Thunderbird Owner's Manual

Speed control cannot reduce the vehicle speed if
it increases above the set speed on a downhill. If
your vehicle speed is faster than the set speed
while driving on a downhill in Overdrive, you
may want to shift to the next lower gear to
reduce your vehicle speed.
If your vehicle slows down more than 10 mph
(16 km/h) below your set speed on an uphill,
your speed control will disengage. This is
normal. Pressing Resume will re-engage it.
To keep your vehicle under control, do
not use speed control in heavy traffic or
on roads that are winding, slippery, or
unpaved.

To Set a Higher Set Speed

Press and hold SET ACCEL. Release the
switch when the desired vehicle speed is
reached. OR
Press and release SET ACCEL. Each press
will increase the set speed by 1 mph
(1.6 km/h). OR
Accelerate with your accelerator pedal, then
press SET ACCEL.
You may accelerate with the accelerator pedal at
any time during speed control usage. Releasing
the accelerator pedal will return your vehicle
speed to the previously programmed set speed.
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