Installation Instructions -- Emergency Vehicle Roof Panel Lamp
Wiring to the accessory can be done by either directly connecting the wire in
the roof to the accessory (Option A) or by using Wiring Harness Package part
number 12150250 obtained from GM Service Parts (Option B).
- Disconnect the negative (-) battery cable at the battery.
- Make the electrical connections using either option A or option
B.
Notice: Pulling the wiring harness through a panel hole
that has sharp edges may cause damage to the wire and/or wire insulation. Remove sharp
edges from the panel hole before pulling the wire through it.
Option A: Roof Wires Directly to Accessory
- Drill a 3/8 inch to 1/2 inch (10 to 13 mm) hole in the outer
roof panel in the area shown in the illustration. The hole should only go through
the outer panel. Remove all sharp edges from the drilled hole.
- Pull out the wiring harness being careful to avoid scraping the insulation
on the edge of the hole.
- Extend the wiring harness to the accessory.
- Connect the BROWN wire to the accessory hot terminal.
- Connect the BLACK wire to the accessory ground terminal.
- Cover the hole in the roof with a durable sealant such as silicone rubber
sealer.
Notice: If you leave your radio or other accessories on
during the jump starting procedure, they could be damaged. The repairs would not be
covered by your warranty. Always turn off your radio and other accessories when jump
starting your vehicle.
Option B: Use Wiring Harness Package 12150250. Obtain from GM Service Parts
through the GM Dealership
- Drill a 1.25 inch (32 mm) hole in the outer roof panel in the
area shown. The hole should only go through the outer panel. Remove all sharp edges
from the drilled hole.
- Pull out the wiring harness being careful to avoid scraping the insulation
on the edge of the hole.
- Cut the wire to length. Install terminals to wire ends and insert into
the connector. The BROWN wire goes in cavity A and the BLACK wire in cavity B. Push
in the secondary lock to retain the wires.
- Attach the harness assembly from the package to the accessory. Cover with
the supplied conduit for added protection. Connect the ORANGE wire to the accessory
hot terminal and the BLACK wire to the ground.
- Complete the connection from the roof harness to the extension harness.
Cover the mated connector with the supplied foam. Push the foam covered connection
and excess wire through the roof panel hole.
Restoring Power
- Be sure that the auxiliary lamp switch is OFF.
- Vacate the vehicle and reconnect the battery cable.
- Turn the auxiliary lamp switch on. The accessory should now be working.
If it is not working, check the connections.
- After ensuring that the accessory is working properly, install the grommet
in the hole. Seal with silicone sealer to prevent water leakage.
Notice: Overloading the vehicle's electrical system may
damage your vehicle's accessories. Do not overload the vehicle's system by having
unnecessary accessories on at the same time.
Option B
Harness Assembly
Grommet (Roof)
Harness Connector, Secondary Lock and Terminal
Foam Insulator (Adhesive-Backed)
Vehicle Outer Roof Panel
Maintenance
The circuit is fed from the # 2 post on the underhood electrical center
and protected by the fuse labeled "# 2 Post" located
in the electrical center. Always replace the fuse with a 30 amp maxi-fuse.
Notice: Before modifying or adding any wiring, be sure
that it will work properly with your vehicle's wiring system. Because there are so
many modifications that can be made for many different bodies and accessories, GM
cannot take responsibility for any changes made. Such changes may not be covered by
your GM Warranty. Have the work done by an experienced electrical technician.
All wiring must be properly protected by fuses, etc. and must be routed properly
so that it will not be cut, pinched or rubbed by other parts of the vehicle. Do not
route wiring in areas where it will be very hot. Be sure not to overload the vehicle's
wiring, connectors and components. All added wire must be at least the same size as
the wire being attached to for proper fuse protection.
Installation Instructions -- 12 Volt Accessory Power Supply
- Disconnect the negative (-) battery cable at the battery. The negative
(-) battery cable must be disconnected before the positive wiring lead is connected
to the power accessory.
- Locate the power supply harness under the instrument panel near the right
side of the vehicle. The wire bundle consists of the pink ignition (IGN) , orange
battery (BAT) and black negative (NEG) wire feeds.
- Remove the tape to release the wire bundles from the power supply harness.
- Remove the 40 amp MegaFuse that is taped to the wire bundle. Set
aside for installation, after equipment wiring is complete.
- Prepare the wires that are to be used to connect the power accessory.
Do not remove the unused wires. Tape unused wires back in their original position
under the instrument panel.
- Complete the wiring installation of the customer added accessory with
additional wire required for the specific electrical accessory power connection. The
wire gage, 12 gage (3.0 mm), should be the same as the wiring of the
installed harness.
- The ignition must be turned to OFF or ACC prior to attaching the cables
to the battery, or serious damage to the Vehicle Control Module (VCM) may result.
The windshield wiper switch and the radio must be turned off before attaching
cables to the battery.
- Disconnect the positive (+) battery cable at the underhood power distribution
center. Remove the nut from the 8 mm stud (See illustration).
- Install the 40 amp MegaFuse (from step 4) in the front holder
on the underhood power distribution center over the stud. Reinstall the positive (+)
battery cable with the mounting screw through the MegaFuse terminal. Replace the 8 mm
nut on the stud. Torque both the nut and screw to 1.3-2.7 lb.-ft (6-12 N·m).
- Reconnect the negative (-) battery cable to the battery. Torque the bolt
to 12.5 lb-ft. (17 N·m).
- Reset the clock time and radio pushbuttons as desired.
Underhood Power Distribution Center
The IGN A and IGN B connections have voltage supplied and are
hot when the ignition is turned to ACC or RUN (pink color wire).
The BAT A and BAT B connections have voltage supplied and are
hot at all times (orange color wire).
The combined electrical load of IGN A and BAT A must not exceed
21 amps (250 watts). Additionally, the combined electrical load of IGN B
and BAT B must not exceed 21 amps (250 watts). The combined electrical
load of all circuits must not exceed 28 amps (340 watts).