1999 GMC SAFARI heater

6-19 Installing the Engine Cover
1. Lift the engine cover into the vehicle and slide it all
the way forward. Make sure the rubber seal is over
the latches.
2. Install the two bolts at the engine cover.
3. Put the heater duct over the engine cover studs.
Push up on the duct gently until it snaps into place.
4. Reconnect the electrical connectors.
5. Install the engine cover extension by gently
squeezing the sides and sliding it into place. Make
sure all of the fastener clips engage and the extension
fits properly in place. Replace and tighten the
two screws.
6. Install the two nuts to secure the extension in place.
Engine Air Cleaner/Filter
Refer to the Maintenance Schedule to determine when to
replace the air filter and the crankcase ventilation filter.
See ªScheduled Maintenanceº in the Index.
1. To remove the air filter, lift the hood.
2. Unsnap both clips.
3. Remove the top.
4. Change the filter.
5. Snap both clips to secure the air cleaner.
Be sure the air cleaner lid is correctly positioned to seal
out dust and contaminants that are harmful to your engine.
Make sure the fresh air hose is still attached after the
filter change.

6-26 What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, see ªEngine Overheatingº in
the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as they should.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.
What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.

6-27
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.

6-66
Fuse/Circuit
Breaker Usage
ECM
-B Fuel Pump Relay and Motor,
VCM, Oil Pressure
Switch/Sender
HORN Horn Relay and Horn
A/C COMP A/C Enable Relay
and Compressor
RR HTR/AC Rear Heater and A/C
ATC Active Transfer Case
FRT HVAC Front Heater and A/C
ENG
-I Oxygen Sensors, Camshaft
Position Sensor, Mass Air Flow
Sensor, Evaporative Emission
Canister Vent Solenoid
IGN
-E A/C Enable Relay Coil
ECM
-I Fuel Injectors 1-6, Crankshaft
Position Sensor, VCM, Coil
Driver Module (EST),
Ignition CoilFuse/Circuit
Breaker Usage
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
DIODE
-A/C Coil A/C
LIGHTING Courtesy Fuse, Pwr. Adj.
Mirrors Fuse, TBC
-Battery Fuse
BATT Power ACCY CB, Stop/Hazard
Fuse, Auxiliary Power Fuse,
Cigarette Lighter Fuse,
Radio Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABS Electronic Brake
Control Module
RAP Radio Accy, Power Windows
HTD MIR/RR
DEFOGRear Window Defogger,
HVAC Control Head
*A fuse puller is included in the underhood electrical
center. You will also find spare fuses.

6-68
Capacities and Specifications
All capacities are approximate. English and metric
conversions are given. See refrigerant charge label under
the hood for charge capacity information and
requirements. Please refer to ªRecommended Fluids and
Lubricantsº in the Index for more information.
Engine Specifications
Engine ªVORTECº 4300 V6 CSFI*. . . . . . . . . . . . . .
RPO L35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing Order 1
-6-5-4-3-2 . . . . . . . . . . . . . . . . . . . . . .
Horsepower 190 at 4,400 rpm. . . . . . . . . . . . . . . . . . .
*Central Sequential Fuel Injection
Wheel and Tires
Wheel Nut Torque 100 lb-ft (140 N´m) . . . . . . . . . . .
Tire Pressures See ªLoading Your Vehicleº. . . . . . . . .
in the Index.
Cooling System Capacity
Quantity*
without
Rear HeaterQuantity*
with
Rear Heater
13.5 quarts (12.8 L) 16.5 quarts (15.6 L)
After refill, the level must be checked.
*All quantities are approximate.
Crankcase Capacity
Quantity* with Filter 4.5 quarts (4.3 L). . . . . . . . . . .
After refill, the level must be checked. Do not overfill.
*All quantities are approximate.
Fuel Tank Capacity
Standard Tank 27.0 gallons (101.8 L). . . . . . . . . . . . .
Transmission Capacity
Automatic Transmission
(Drain and Refill) 5.0 quarts (4.7 L). . . . . . . . . . . .