GMC 1998 Safari Owner's Manual page 119

1. Move the cruise control switch to ON.
2. Get up to the speed you want.
3. Press in the SET button
at the end of the lever
and release it.
Once you're going about
25 mph (40
km/h)
or more,
you can move the cruise
control switch from ON
to R/A for about
1 1/2 seconds.
You'll go right back up to your chosen speed and
stay there.
4. Take your foot off the accelerator pedal.
Resuming a Set Speed
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.
Remember, if you hold the switch at R/A longer than
1 1/2 seconds, the vehicle will keep going faster until
you release the switch or apply the brake. So unless you
want to go faster, don't hold the switch at WA.
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