Sunday, September 1, 2013

Step 2: Audio

It's been a while since I worked on this project, but finally graduating from college has given me a little more time. Now I put the audio components in the car. Thanks to some members over at, I selected a Pyle 4-Channel 800-watt waterproof micro marine amplifier and the appropriate wiring harness for my truck.

First, I removed the stereo. If you have a late-90s Chevy pickup like I had, you'll need to watch this video to remove the faceplate, and then disconnect the stereo harness and antenna to remove the factory stereo. Then before I could connect the amp, I had to splice the wires into the harness. Below is a picture of the in-car harness plug and the panel I later installed the volume knob on:
After removing the stereo
The harness came with a wire color code guide, which I'll reproduce here:
  • Yellow: 12 Volt Battery/Constant
  • Red: 12 Volt Ignition/Switched
  • Black: Chassis Ground
  • Black/White: Factory Amplifier Ground
  • Blue: Power Antenna/Factory Amplifier Remote Turn On
  • Blue/White: Factory Amplifier Remote Turn On
  • Orange: Illumination/Dimmer
  • Orange/White: Illumination/Dimmer
  • Orange/Black: Illumination Ground/Dimmer Ground
  • Brown: Mute/Not Used
  • White: Left Front Positive (LF+)
  • White/Black: Left Front Negative (LF-)
  • Grey: Right Front Positive (RF+)
  • Grey/Black: Right Front Negative (RF-)
  • Green: Left Rear Positive (LR+)
  • Green/Black: Left Rear Negative (LR-)
  • Violet: Right Rear Positive (RR+)
  • Violet/Black: Right Rear Negative (RR-)
The amplifier also came with a wiring guide, which can be found here. The most important part was getting the power right. Since I wanted to have it on only when the truck was on, I wired it in the following way:
Power wiring arrangement

The yellow wire (12V battery/constant) from the harness connects to the red (Battery + 12DC) wire of the amp, which is protected by a 10A fuse. The black (chassis ground) from the harness connects to the black (Battery -, Ground) wire of the amp. The red wire (12V ignition/switched) from the harness connects to the blue wire (remote turn on) of the amp. This configuration allows the amp to receive power only after turning on the ignition.

Next I had to connect the speaker wiring. The amplifier end has 8 wires with female bullet connectors (positive/negative for 4 channels). Unfortunately, I was not careful enough in checking the packing for the amp and ended up soldering my own male bullet connectors onto the harness speaker connections. Yes, the amplifier comes with male bullet connectors on wires that can simply be crimped together to the harness speaker wires. The colorings all matched up easily (Violet to Violet, Gray/Black to Gray/Black). As you can see in the below picture, the blue and orange wires are not used so I capped them with beanies to prevent a short.

Speaker wiring bullet connectors
Then I simply plugged the bullet connectors together and the initial setup is complete!
Completed wiring connections
The amplifier came with a volume control knob, and I had an open (unused) panel above the cargo lamp. So I drilled a hole in the panel, and attached the knob. The knob comes with adhesive backing on the back, so simply peel off the protective cover and stick it on there. The volume knob also shuts off power to the amp when turned all the way down.

Volume control knob installation

As you can see in the above picture, the cavity that held the stereo has no floor, and simply has the connectors for the volume control down below. So I made a floor out of some aluminum sheeting I had lying around. It is pretty thin, so I just used metal shears to cut out a 7" by 8" section:
Aluminum "floor"
The amp comes with mounting hardware (screws, lockwashers, and washers). So I drilled slightly smaller holes in the aluminum, and attached the amp towards the back of the plate.
Attached amplifier

Then the only thing remaining was to slide the sheet assembly into the cavity, attach the harness, and it worked flawlessly. Well, almost flawlessly. I have noticed in the past day some feedback on the line from the car's electrical system. So I will have to install a power filter at some point.
Installed amplifier (note dangling 3.5mm input)

Overall, the amplifier and harness worked excellently and I was happy with the fairly easy installation.

Status update:
Time spent (4 days): 15 hours
Cost expended (prices given include paid shipping): $173.32 ($50.53 + $122.79 previous. If you don't have spare aluminum and electrical beanies, you may have to spend a few dollars to buy some)