PIONEER GM-X742
Service Manual

Connecting the Unit
CAUTION
� Disconnect the negative (�) terminal of the battery to avoid the risk of short-circuit and damage to the unit. � Secure the wiring with cable clamps or adhesive tape. To protect the wiring, wrap adhesive tape around it where they lie against metal parts. � Do not route wires where they will get hot, for example where the heater will blow over them. If the insulation heats up, it may become damaged, resulting in a short-circuit through the vehicle body. � Make sure that wires will not interfere with moving parts of the vehicle, such as the gearshift, handbrake or seat sliding mechanism. � Do not shorten any wires. Otherwise the protection circuit may fail to work when it should. � Never feed power to other equipment by cutting the insulation of the power supply wire to tap from the wire. The current capacity of the wire will be exceeded, causing overheating.

Connection Diagram
Fuse (30 A) Grommet Special red battery wire [RD-223] (sold separately). After making all other connections at the amplifier, connect the battery wire terminal of the amplifier to the positive (+) terminal of the battery. Fuse (30 A) Ground wire (black) [RD-223] (sold separately). Connect to metal body or chassis.

Connecting the Power Terminal
� Always use the special red battery and ground wire [RD-223], which is sold separately. Connect the battery wire directly to the car battery positive terminal (+) and the ground wire to the car body.

4. Connect the wires to the terminal.
� Fix the wires securely with the terminal screws. GND terminal Power terminal System remote control terminal System remote control wire Ground wire

3. Connect the speaker wires to the speaker output terminals.
� Fix the speaker wires securely with the terminal screws. � Connect the speaker wires, passing them through the terminal cover. Terminal screw

Connecting the Speaker wires
The speaker output mode can be two-channel (stereo), one-channel (mono). Connect the speaker leads to suit the mode according to the figures shown below.

1. Pass the battery wire from the engine compartment to the interior of the vehicle.
� After making all other connections to the amplifier, connect the battery wire terminal of the amplifier to the positive (+) terminal of the battery. Engine Fuse (30 A) compart- Interior of ment the vehicle Battery wire

Two-channel mode (stereo)

Terminal Speaker output terminal Speaker wire cover (Left) Speaker (Right)

To prevent damage

� Do not ground the speaker wire directly or connect a negative (�) lead wire for several speakers. � This unit is for vehicles with a 12-volt battery and negative grounding. Before installing it in a recreational vehicle, truck, or bus, check the battery voltage. � If the car stereo is kept on for a long time while the engine is at rest or idling, the battery may go dead. Turn the car stereo off when the engine is at rest or idling. � If the system remote control wire of the amplifier is connected to the power terminal through the ignition switch (12 V DC), the amplifier will always be on when the ignition is on� regardless of whether the car stereo is on or off. Because of this, the battery could go dead if the engine is at rest or idle.

� Speakers to be connected to the amplifier should conform with the standards listed below. If they do not conform, they may catch fire, emit smoke or become damaged. The speaker impedance must be 1 to 8 ohms for stereo connection, and 2 to 8 ohms for monaural and other bridge connection. � Install and route the separately sold battery wire as far away as possible from the speaker wires. Install and route the separately sold battery wire and ground wire, speaker wires, and the amplifier as far away as possible from the antenna, antenna cable and tuner. � Cords for this product and those for other products may be different colors even if they have the same function. When connecting this product to another product, refer to the supplied Installation manuals of both products and connect cords that have the same function. RCA output jack

RCA input

Amplifier with RCA input jacks

Connecting wires with RCA pin plugs (sold separately). Car stereo with RCA output jacks External Output RCA input jack Fuse (30 A) Drill a 14 mm Positive terminal hole into the Insert the O-ring rubber vehicle body. grommet into the vehicle body.

Connecting the Speaker Output Terminals
1. Expose the end of the speaker wires by about 10 mm and twist using nippers or a cutter.
Twist

4. Push on the terminal cover.

One-channel mode (mono)

2. Twist the battery wire, ground wire and system remote control wire.
Twist
10 mm

Speaker (Mono)

Front side

GM-X942 Speaker Channel
Two-channel One-channel

Speaker Type
Subwoofer Other than subwoofer Subwoofer Other than subwoofer

Power
Nominal input: Min. 120 W Max. input: Min. 200 W Nominal input: Min. 330 W Max. input: Min. 600 W GM-X942: Fuse (30 A) � 2 GM-X742: Fuse (20 A) � 2 Back side

3. Attach lugs to wire ends. Lugs not supplied.
� Use pliers, etc., to crimp lugs to wires. Lug

2. Attach lugs to speaker wire ends. Lugs not supplied.
� Use pliers, etc., to crimp lugs to wires. Lug Speaker wire

GM-X742 Speaker Channel
Two-channel

Ground wire Lug

Speaker Type
Subwoofer Other than subwoofer Subwoofer Other than subwoofer

Power
Nominal input: Min. 100 W Max. input: Min. 160 W Nominal input: Min. 270 W Max. input: Min. 480 W Speaker output terminal See the �Connecting the Speaker wires� section for speaker connection instructions. System remote control wire (sold separately). Connect the male terminal of this wire to the system remote control terminal of the car stereo (SYSTEM REMOTE CONTROL). The female terminal can be connected to the autoantenna relay control terminal. If the car stereo does not have a system remote control terminal, connect the male terminal to the power terminal through the ignition switch.

Battery wire

One-channel