1998 GMC SIERRA auxiliary battery

Trailer Wiring Harness
A. Light-Duty Wiring Harness
B. Additional Heavy-Duty Wiring
C. Tie Straps
A eight-wire harness is stored under the rear end of your
vehicle. Five wires (A) are located between the rear
bumper and the spare tire, near the center. This wiring
harnewis tie-strapped to the taillamp and stoplamp
harness. Three wires (B) (light gauge white, blue and
orange) are located at
the rear left hand frame rail. This
harness has a
30 amp battery feed wire and no
connector, and should be wired
by a qualified electrical
technician. After choosing an aftermarket mating
connector pair, have the technician attach one connector
to the eight-wire trailer harness and the other connector
to the wiring harness on the trailer. Be sure that the
wiring harness on the trailer is strapped to the trailer’s
frame and leave
it loose enough so that the wiring
doesn’t bend or break, but not
so loose that it drags on
the ground. The technician can use the following color
code chart when connecting the wiring harness to
your trailer.
0 Brown: Rear Lamps
0 Yellow: Left Stoplamp and Turn Signal
0 Dark Green: Right Stoplamp and Turn Signal
0 White (Heavy Gauge): Ground
0 Light Green: Back-up Lamps
0 White (Light Gauge): Center High-Mounted
Stop Lamp
0 Blue: Auxiliary/Electric Trailer Brake Circuit
0 Orange: Fused Auxiliary Circuit
Store the harness
in its original place. Wrap the harness
together and tie
it neatly so it won’t be damaged.
4-60
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2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection
you don’t want. You wouldn’t be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility
of the vehicles rolling, set
the parking brake firmly on both vehicles involved
in the jump start procedure. Put an automatic
transmission in
PARK (P) or a manual transmission
in NEUTRAL (N).
If you have a four-wheel-drive
vehicle, be sure the transfer case is not in
NEUTRAL
(N).
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn
off all lamps
that aren’t needed as well as radios. This will avoid
sparks and help save both batteries. In addition, it
could save your radio!
I NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
4. Open the hoods and locate the batteries. Find the
positive
(+) and negative (-) terminals on each battery.
If your vehicle has air conditioning, the auxiliary
electric fan under the hood can start up even
when the engine is not running and can injure
you. Keep hands, clothing and tools
away from
any underhood electric fan.
5-4
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STARTER RELAY
[-I
[-I
[T)
I BLOWER
n STOPiHAZ
Name
ECM-B RR DEFOG
IGN-E
FUEL
SOL
GLOW PLUG
Usage
Horn, Underhood Lamps
Auxiliary Fan
Injectors, PCM/VCM
Not Used
Air Conditioning
Not Used
Ignition Switch, EGR, Canister
Purge, EVRV Idle Coast Solenoid,
Heated
02, Fuel Heater
(Diesel Engine), Water Sensor
(Diesel Engine)
HTD ST-RR Not Used
LIGHTING Headlamp and Panel Dimmer
BATT Battery, Fuse Block Busbar
IGN-A Ignition Switch
IGN-B Ignition Switch Switch,
Fog and Courtesy Fuses
ABS Anti-Lock Brake Module
BLOWER High Blower Relay
STOP/HAZ Stoplamps
HEATED SEATS Not Used
6-75
Usage
Fuel Pump, PCM/VCM
Rear Window Defogger
Auxiliary Fan Relay Coi
il, AIC
Compressor Relay, Hot Fuel
Module, Dual Tanks
Fuel Solenoid (Diesel Engine)
Glow Plugs (Diesel Engine)
Name
HORN
AUX FAN
ECM- 1
HTD ST-FR
AIC HTD MIR
ENG-
1
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