Marine stereo technology has changed drastically in recent years, and it’s high time for your boat to catch up with these trends. Many new sound systems are now capable of playing a variety of music formats, including CDs, WMAs and MP3s. Other modern advances include connectors for portable MP3 players, satellite radio receivers and remote-control devices. For this example, a Clarion CMAS-5 Marine Stereo and a set of Poly-Planar speakers — both of which have been supplied by West Marine (www.westmarine.com) — are installed into an older boat.

Step 1

If you’re not replacing an existing system, begin by choosing an appropriate mounting location to avoid water damage to internal components. Also, the unit must be mounted within 30 degrees of the horizontal plane. With this project, there’s an existing older unit that needs to be removed before the new one can be installed. Luckily, it’s in a good spot on the dashboard and is accessible from behind. It’s secured with two nuts behind the tune/volume knobs and a nut holding the back of the unit to a support bracket. In such a situation, unplug the wire harness from the stereo unit and slide it out of the dash compartment. Some older units may fit snugly, which could require a flat-head screwdriver to assist in removal. Be careful not to damage the unit, unless you plan on discarding it anyway.

 Step 2

BW’s installation boat has only one set of speakers mounted on each side of the console near the front seats. Carefully pry off the old covers and then remove the two or three screws holding the speakers in place. Inspect the existing wires and connectors for cracks or corrosion, and replace as needed. Pay close attention to the connectors on the existing wiring. These may not fit the new speakers, so they might need to be replaced. If the existing wires are in good shape, you won’t have to run new speaker wire. Most hardware stores sell connectors in various sizes if you need them. Plug the connectors into the new speakers and pay attention to the wires. One wire should have a black stripe running along the outer cover and connects to the negative speaker terminal. Reattach the screws and new speaker covers to complete this step.

Step 3

 This particular boat doesn’t have rear speakers to replace. For boats that don’t have rear speakers, consider “boxed” speakers to eliminate the cutting needed to create speaker openings in side panels. Poly-Planar box speakers work the best for the installation in this particular case. These are mounted in the back of the side wells, out of the path of any weather. If possible, drill holes from the side well down into the open wiring channel under the side well. The bracket is secured with two bolts, nuts and lock washers. If the boat doesn’t have rear speakers, run new speaker wire to the wiring harness under the dash where the receiver will be installed. Install the proper connectors on the speaker wire and plug into the terminals on the speakers. Mount the speakers on the brackets using the two thumbscrews provided.

Step 4

 Rewire the new harness on the back of the unit to the existing speaker wires and then to the power source. The new unit will most likely have a schematic that identifies each wire’s purpose. Identify each wire, cut it from the old harness, and then reattach to the new harness using two layers of black polyolefin heat-shrink tubing and a heat gun. Be sure to pay attention to the black stripe on the speaker wire to ensure you connect it to the negative speaker wire in the new harness. Now, slide the new unit into the old opening and secure it with the two nuts on the front casing and the support bracket in the back. A jigsaw can be used to resize if necessary. Finally, plug the wire harness and FM antenna connector into the stereo receiver and reattach them to the negative battery terminal.