JL Audio HD900/5 owner manual +12V Battery Connection, Power Wire Requirements, Fuse Requirements

Power and Turn-on Connections Before installing the amplifier, disconnect the

negative (ground) wire from the vehicle’s battery. This will prevent accidental damage to the system, the vehicle and your body during installation.

+12V Battery Connection

You will need to connect a power wire to the vehicle’s positive battery terminal, using an appropriate power ring or specialized battery terminal connector, such as the JL Audio XB-BTU. This connection must be tight and corrosion-free to ensure proper connectivity. This wire MUST be fused appropriately for safety. Any positive power wires run through metal barriers (such as firewalls), must be protected with a high quality insulating grommet to prevent damage to the insulation of the wire. Failure to do so may result in a dangerous short circuit.

Power Wire Requirements

The HD900/5’s “+12 VDC” and “Ground” connections are designed to accept 4 AWG power wire. 4 AWG pure copper wire is

the minimum recommended wire size for this amplifier. Use of smaller gauge wire (including cheap wire that is fraudulently sold as 4 AWG wire) can create a fire hazard.

If you are installing the HD900/5 with other amplifiers and wish to use a single main power wire, use 2 AWG or 1/0 AWG pure copper wire as a main power wire. This 2 AWG or 1/0 AWG power wire should terminate into a distribution block mounted as close to the amplifiers as possible and should connect to the HD900/5 with 4 AWG pure copper power wire, with each smaller wire fused appropriately for each amplifier or other electronics in the system.

Please note that lower AWG numbers mean bigger wire and vice-versa (1/0 AWG is the largest, 2 AWG is smaller, then 4 AWG, then 8 AWG, etc.).

We do not recommend the use of “copper-clad aluminum wire” or “CCA” wire because this wire is significantly less conductive than pure copper wire. Only use pure copper power wire, such as JL Audio’s MetaWire™. Tinned copper wire (silver color) is acceptable as the tin-plating is only a very minor component of the wire.

Fuse Requirements

The installation of a fuse on the main power

wire, within 18 wire inches (45 cm) of the positive battery terminal is vital to protect the wire and the vehicle from fire in the event of a collision or short-circuit. The fuse value at each power wire should be just high enough for all of the equipment being run from that power wire. Do not use a fuse with a value that far exceeds the total fuse rating of the electronics connected to the wire.

If only the HD900/5 is being run from a single power wire, install a 60A fuse to protect the wire: AGU (big glass fuse). AFS (small blade fuse) or MaxiFuse™ (big plastic- body fuse) types are recommended.

If other amplifiers are also being powered from a main power wire and exceed 80 amps in total fuse rating, we recommend the use of an ANL (large-blade) fuse and holder. Each amplifier can then be fused independently at the outputs of the power distribution block. Use JL Audio part XC-FOA-2PAK and appropriate MaxiFuse™ type fuses with JL Audio distribution blocks.

Please consult with your JL Audio dealer to make sure that the wire, fuse holder and fuse ratings are appropriate for your system’s needs. The safety of your installation depends on appropriate power connections and fuse protection.

Ground Connection

The chassis ground connection must be made using 4 AWG pure copper wire and should be kept as short as possible, while accessing a solid piece of sheet metal in the vehicle. The surface of the sheet metal should be sanded at the contact point to create a clean, metal-to-metal connection between the chassis and the termination of the ground wire with a brass or copper power ring.

6 JL Audio - HD900/5 Owner’s Manual