1995 GMC SIERRA cooling

Before using your vehicle's air conditioning. open the windows to clear the.
vehicle of hot air.
Using the recirculation function can also help. See "Recirculation Buttor:"
in this section for more information.
The knob on the left side of the heating system control panel controls the
fan speed. The knob has four speed positions. To increase the air
flow. move
the knob toward
HI. To decrease the air flow. move it toward LO. To turn
the fan off. move the knob
to OFF. If you have the air conditioner on.
moving the fan knob
to OFF also turns off' the A/C compressor.
The middle knob on the control panel lets you select the relative
temperature of the air flowing into the passenger
area of your vehicle. This
knob
will allow you to adjust the relative air temperature independently of'
the function knob setting. Move the knob right toward the red area for
warmer air. Move the knob left toward the blue area for cooler air. With
A/C
on, move the knob to MAX for maximum cooling.
This setting puts the system
in the recirculation mode and helps to maximize
your air conditioner's performance and your vehicle's fuel economy. This
setting also cools the air the fastest. After the vehicle's interior reaches
a
comfortable temperature, move the knob clockwise to place the air
conditioning system
in the normal mode.
The right knob
on the control panel changes the heatedair conditioning
setting.
VENT - This setting, with the arrow pointing at the figure's head. directs
air through the instrument panel vents.
VENT/HEAT
- Use this setting, with the arrows pointing at the figure's
feet and head, to divide airflow between the heater floor vents and
instrument panel vents.
HEAT
- This setting. with the arrow pointing at the figure's feet. directs air
through the heater floor vents. This setting is useful for cold weather.
HEAT/DEFROST
- Use this setting, with the arrow pointing at the figure's
feet and the defroster symbol near the figure's head. to divide airflow
between the heater floor vents and windshield.
DEFROST
- This setting with the defrost symbol directs air through the
windshield defroster vents. This setting is useful when you have fog
or ice
on the windshield.
The control knob can be placed
in any position between two heatedair
conditioning settings to blend the flow
of air. The closer the knob is to a
setting symbol, the more the air flow will represent that symbol's air flow
arrows.
RECIRCULATION
BUTTON - This button, between the left and middle
knobs, allows the air inside your vehicle
to be recirculated. This setting
helps to maximize your air conditioner's performance and your vehicle's
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fuel economy. This setting also cools the air the fastest and can be used to
keep “unwanted odors” and/or dust from entering the vehicle. When using
the air conditioner, turn off recirculation after the vehicle reaches
a
comfortable interior temperature.
When
the right knob on the control panel is between HEAT and DEFROST,
the recirculation feature will not function.
A/C - This button, between the middle and right knobs. allows the air
coming into your vehicle
to be cooled and directed through the instrument
panel vents. This setting is useful for normal cooling
on hot days. When you
first use
A/C with the recirculation button pushed in, turn off recirculation
as soon as the vehicle reaches a comfortable interior temperature.
Engine Coolant Heater
If your vehicle has a diesel engine, it is equipped with an engine coolant
heater.
An engine coolant heater is optional on gas engine vehicles. If you
use the engine coolant heater before starting your engine
(in cold weather
(20” F, (-8” C), or lower) your heating system will produce warmer air
faster, to heat the passenger compartment
in cold weather.
The use
of an engine coolant heater also reduces the time it takes for the
engine to reach normal operating temperature. and shortens the time it takes
the heater
to reach full output. For more information, See “Engine Coolant
Heater” in the Index.
Diesel Engine Heater Output
If you idle your diesel engine for a long time when it’s cold outside, your
heater may blow out cool air. This is normal. When you increase the engine
speed, your heater should blow out warmer air.
If it doesn’t, your coolant
level may be too low. See “Engine Coolant”
in the Index to see how to
check your coolant level.
Rear Window Defogger (Option)
You can tell if your vehicle has this option by looking at the rear window. If
you see lines running across the glass, you have it. These are the wire-like
elements which heat your window.
I NOTICE:
Scraping the inside of your rear window could cut and damage
the defogger.
Your warranty would not cover this damage. And,
don’t put decals there, you might have to scrape them off.
For best results, clear the window of as much snow or ice as possible first.
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After Off-Road Driving
Remove any brush or debris that has collected on the underbody, chassis or
under the hood. These accumulations can be
a fire hazard.
After operation
in mud or sand, have the brake linings cleaned and checked.
These substances can cause glazing and uneven braking. Check the body
structure, steering, suspension. wheels, tires, and exhaust system for
damage.
Also, check the fuel lines and cooling system for any leakage.
Your vehicle
will require more frequent service due to off-road use. Refer
to the Maintenance Schedule for additional information.
Driving at Night
Night driving is more dangerous than day driving. One reason is that some
drivers are likely
to be impaired - by alcohol or drugs, with night vision
problems,
or by fatigue.
Here are some tips on night driving.
0 Drive defensively.
Don’t drink and drive.
Adjust your inside rearview mirror to reduce the glare from headlamps
Since you can’t see as well, you may need to slow down and keep more
behind
you.
space
between you and other vehicles.
a Slow down, especially on higher speed roads. Your headlamps can light
up only
so much road ahead.
0 In remote areas, watch for animals.
If you’re tired, pull off the road in a safe place and rest.
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What can you do about highway hypnosis? First, be aware that it can
happen.
Then here are some tips:
0 Make sure your vehicle is well ventilated, with a comfortably cool
Keep your eyes moving. Scan the road ahead and to the sides. Check
interior.
your mirrors and your instruments frequently.
If you get sleepy, pull off the road into a rest, service, or parking area
and take a nap, get some exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
I
Driving on steep hills or mountains is different from driving in flat or
rolling terrain.
If you drive regularly in steep country, or
if you’re planning to visit there,
here are some tips that can make your trips safer and more enjoyable. (See
“Off-Road Driving” in the Index for information about driving off-road.)
Keep your vehicle in good shape. Check all fluid levels and also the
brakes, tires, cooling system and transmission. These parts can \
work
hard on mountain roads.
Know how to go down hills. The most important thing to know is this:
let your engine do some of the slowing down. Shift to a lower gear
when you go down a steep or long hill.
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When You Are Ready to Leave After Parking on a Hill
1. Apply your regular brakes and hold the pedal down while you:
Start your engine:
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re pulling a trailer. See
the Maintenance Schedule
for more on this. Things that are especially
important
in trailer operation are automatic transmission fluid (don’t
overfill), engine oil, axle lubricant, belt, cooling system, and brake
adjustment. Each of these is covered
in this manual, and the Index will help
you find them quickly. If you’re trailering, it’s
a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch
nuts and bolts are tight.
Trailer Lighting Systems Wiring
See “Trailer Wiring Harness” in the Index.
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Cooling System - Gasoline Engines
When you decide it’s safe to lift the hood, here’s what you’ll see:
A. Coolant recovery tank
B. Engine fan(s)
C. Radiator pressure cap
I A CAUTION:
If your vehicle has air conditioning, the auxiliary electric fan
under the hood can start up even when the engine is not runn\
ing
and can injure you. Keep hands, clothing and tools away from any underhood electric fan.
If the coolant inside the coolant recovery tank is boiling, don’t do anything
else
until it cools down.
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The coolant level
should be a1 or above
the
COLD 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 CAUTION:
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.
NOTICE:
Engine damage from running your engine without coolant isn’t
covered
by your warranty.
If there seem to be no 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.
How to Add Coolant to the Coolant Recovery Tank
If you haven’t found a problem yet, but the coolant level isn’t at or above
the COLD mark, add
a SO/SO mixture of c.lea12 water (preferably distilled)
and
a proper antifreeze at the coolant recovery tank. (See “Engine Coolant”
in the Index for more information about the proper coolant mix.)
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When the coolant in the coolant recovery tank is at or above the COLD
mark. start your vehicle.
If the overheat warning continues, there’s one more thing you can try. You
can add
the proper coolant mix directly to the radiator, but be sure the
cooling system
is cool before you do it.
A CAUTION:
Steam and scalding liquids from a hot cooling system can blow
out and burn you badly. They are under pressure, and if you
turn the radiator pressure cap
- even a little - they can come
out
at high speed. Never turn the cap when the cooling system,
including the radiator pressure cap, is hot. Wait for the cool\
ing
system and radiator pressure cap to cool if you ever have to turn
the pressure cap.
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