GMC 1995 Safari Owner's Manual page 89

Suppose you set your Cruise Control at a desired speed and then you apply
the brake. This, of course, shuts off the Cruise Control. But you don't need
to reset it. Once you're going about 25 mph (40 kmh) or more, you can
move the Cruise Control switch from ON to R/A (Resume/Accelerate) for
about half a second.
You'll
go
right back up to your chosen speed and stay there.
Remember, if you hold the switch at R/A (Resume/Accelerate) longer than
half a second, the vehicle will keep going faster until you release the switch
or apply the brake. You could be startled and even lose control. So unless
you want to go faster, don't hold the switch at R/A (Resume/Accelerate).
To Increase Speed While Using Cruise Control
While your cruise control switch is in the ON position, here are two ways to
go to a higher speed.
Use the accelerator pedal to get to the higher speed. Push the button at
the end of the lever, then release the button and the accelerator pedal.
You'll now cruise at the higher speed.
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