W-Body Car Audio

W-Body Car Amplifier Installation Guide

Safety First! Disconnect the negative terminal of the battery during this process.

Where does the amplifier go?

This is the first consideration when you install your amplifier(s). Most people mount the amplifier in the trunk for esthetic and safety reasons. You should also consider the maintenance of your car when installing a car amplifier in the trunk. Too often, people install systems that make replacing the fuel pump or taillight bulbs difficult. Keep in mind that mechanics charge by the hour for labor.

The fuel pump is located just behind the rear seat on the driver's side. The taillight bulbs access panels are at the rear of the trunk, in front of the taillights.

Probably the best place to install the amplifier would be against the rear seat on the passenger's side of the trunk. If you need to take out the amplifier for whatever reason, you don't have holes that will let small amounts of exhaust gases enter the trunk (above the muffler), nor will water splash through the holes left in the wheel wells.

Wiring

You'll need to run wires to and from the amp for three reasons:

1. Power and Ground
2. Signal
3. Speakers

Power

The first wire you should run is from the battery to the trunk. Install a fuse on this wire less than 18" from the battery terminal. If something happens, the fuse will blow close to the battery before anything can happen. The fuse holder can he installed on the driver's side strut tower.

You'll need to run the wire into the passenger compartment. For this, you need an unused "grommet", which is just a fancy word for plug. There's a grommet high on the driver's side firewall between the strut tower and master cylinder. This was used for one of two purposes: the clutch cable on 5-speed equipped cars, or for the shifter cable on column-shift cars. If you have a 5-speed or column shift, you should be okay with 8 gauge wire running alongside the shifter/clutch cable. If you have a floor shifter automatic, you should be fine running four gauge wire through the grommet.

Now that the wire's inside the car, you should run it under the carpet. Pull up the plastic panel in the door jamb by removing the screw towards the back of the piece on the driver's side. The carpet will scoot easily to the side. I ran the wire inside the factory "tunnel" with no ill effects. This will also serve to hide the wire.

You still need to snake this cable into the trunk, but the backseat is in the way. This is simple. There is a bolt on either side of the seat bottom. Remove those two bolts and pull the seat cushion forward. You will see two nuts holding the seatback to the chassis. Remove these, pull the seatback off of the bolts in the chassis, then pull straight up. There will be a thick layer of factory sound deadening. You should be able to run the wire under this and into the trunk.

Signal

Remove the head unit from the dash. You'll be connecting not only the RCA, but also the remote turn on lead. Connect the remote turn on and run it alongside the power wire on the driver's side. Replace the driver's side carpet and panel. The RCA cables should run down the passenger side. Pull the panel that holds the carpet down and run the RCA cables through the factory "tunnel" located underneath the carpet.

Speaker wires

For front speakers, run the wire alongside the RCA cables in the tunnel to the dash, and then to each speaker. Rear speakers are most likely in the rear deck, so run them from the amp to the rear deck.

Ground

Use a self-tapping sheetmetal screw and drill through the metal on the backside of the seat. Remove the screw, and grind off any paint around this area. You want a conductive connection to the chassis. Drill the screw back into the hole you created, this time with the ground wire attached. Use some silicone sealant to seal up the bare paint area to prevent rust.

Connect the Power and RCAs, then reconnect the negative battery terminal.

Test

Re-install the head unit and play some music, making sure everything is connected properly.

To set the gains, read the earlier article on properly setting gains.

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