GMC 1996 Sonoma Owner's Manual page 200

The coolant level should be at the ADD mark. If
it
isn't, you may have a leak in the radiator hoses, heater
hoses, radiator, water pump or somewhere else in the
cooling system.
A
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them.
If
you
do, you can be burned.
Don't run the engine if there is-a leak. If you run
the engine, it could lose all coolant. That could
cause an engine
fire,
and you could be burned.
Get any leak fixed before you drive the vehicle.
1
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
If there seems to be n o leak, start the engine again. See
if the fan speed increases when idle speed
is
doubled by
pushing the accelerator pedal down. If
it
doesn't, your
vehicle needs service. Turn off the engine.
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