WIRING
76
WIRING Tahoe
Your vehicle is equipped with wiring provisions or a 12-volt battery
power supply. Refer to the following information when adding
electrical system. The wiring harness is located below the instrument
panel near the center of the vehicle. The following information
describes the breaker and relay location and provides a wiring
diagram to aid in connecting customer equipment.
The 12-volt batter power is supplied through two underhood mega
fuses, one 125 amp and one 60 amp. This underhood power is fed to
the breaker/relay center via a harness that passes through the driver
side front of the dash, and routed across the instrument pane to a
position forward of the glove box. The breaker/relay center is mounted
to the instrument panel structure forward of the glove box. The center
inc
ludes a plastic bracket,
two relays, two 30-amp breakers and three
50-amp mega circuit breakers.
Two 30 amp breakers supply power from the underhood 60 amp
mega fuse through the contacts of the control relays to a 12 gauge
(3.0. mm
2
) blunt cut wires. These two blunt cut leads are part of wire
coiled under the instrument panel near the center of the vehic
le.
Each relay is operated y a 0.5 mm
2
blunt cut, light or dark blue control
lead includes in a 3 foot (91 cm) loop of wire under the instrument
panel.
Three 50-amp mega circuit breakers,
protected by three fusible links,
supply power directly from the underhood 125-amp mega fuse
through three, 10-gauge (5.0 mm
2
) wires. Two of the wires are routed
through the body harness to a split buss junction block to the left rear
of the cargo area and secured near the jack and tools, This 3 foot (91
cm) of coiled wires can be accessed by removing the cu holder on the
top of the trim panel. The third 10-gauge wire is a blunt cut lead,
which is part of the 3-foot (91 cm) loop of wire coiled under the
instrument panel near the center of the vehic
le.
An 8-gauge (8 mm
2
) ground lead is also provided and it is located
under the front passenger sill plate. It can be accessed by removing
the sill plate and pulling the loop of wire at the front of the plate, the
lead is 3 feet (91 cm) long.
Blunt cut ignition control power and signal circuits are also included
in the wire coiled under the instrument panel near the center of the
vehicle. They include:
• A yellow, 20 Gauge, 10 amp fused circuit, Hot in ACCESSORY, RUN,
or RAP (Retained accessory Power).
• A pink, 20 Gauge, 10 amp fused circuit, Hot in START and RUN
• A Yellow/black, 20 Gauge transmission park signal from the Body
Control Module (BCM), the circuit provides switched power when the
transmission is NOT in P
ARK (P) or NEUTRAL (N) and the ignition is
turned to ON.
The electrical load a
ttached to the park circuit must
nit exceed 0.5 amps (6 watts) and is meant to drive only one relay
coil.
• A dark green/white, 20 gauge Vehicle Speed Signal (VSS) provides
4,000 pulse per mile.
The breaker and relay center is located behind and above the
instrument panel stora
ge compartment.
Remove contents from the
storage tray. Using the tab at the back of the compartment drop the
tray down gently toward the floor. You will find the breaker/relay
center above the right rear corner of the stora
ge compartment.
The
bracket is a
ttached to the instrument panel structure with two screws.
It will hang from the hinge.
WIRING PROVISIONS FOR 12-VOLT BATTER POWER SUPPLY
