Porsche Carrera 4S Aftermarket Stereo Install Factory Amp Bypass

I recently installed an aftermarket stereo and amplifier into a 2003 Porsche Carrera 4S, it was a pretty easy install. If you are going to be working on one of these vehicles, this may help you out.

The factory amp should be located on the driver side of the storage compartment under the hood, right next to the spare tire.

Once the spare tire is removed you should have easy access to the two 10m bolts that secure the metal braket holding the factory amp in place. I fully bypassed the factory amp and installed an aftermarket in its place.

At the factory amp there should be 6 pairs of speaker wires, 2 pairs going to the front dash speakers, 2 pairs going to the front door speakers, and 2 pairs going to the rear speakers. There should also be a heavier gauge pair going to the factory subs if equipped. The front dash speakers, and the front door speakers should meter 2ohms each when testing the speaker wires at the factory amp. The rear speakers should meter 4ohms each. The factory subwoofers if equipped, behind the seats will typically meter 1ohm each (single voice coil). They are normally wired in parallel, so at the factory amp the pair of wires for the subs will meter 1/2 ohm. Depending on the aftermarket amp you are installing, you may need to rewire the subs in series to bring the load up to 2ohm.

This should be the wire colors-

Front Left Dash Positive - Yellow

Front Left Dash Negative - Yellow/Brown

Front Right Dash Positive - Red

Front Dash Right Negative - Red/Brown

Front Left Door Positive - Green

Front Left Door Negative - Brown/Green

Front Right Door Positive - Purple

Front Right Door Negative - Brown/Purple

Rear Left Positive - Blue

Rear Left Negative - Brown/Blue

Rear Right Positive - Blue (Pin 13-14)

Rear Right Negative - Brown/Blue

Once I had my speakers and subs all wired I ran power from the battery, which is only about 5 feet away. I Then grounded the amp, and ran my RCA's and amp turn on/stereo ground wires to the new stereo. 

There should be a rubber grommet on the driver side firewall, where you can run your wires through.

Behind the factory stereo you should have a 12V constant wire on the factory stereo harness. I used that and the ground I ran from the same grounding point as the new aftermarket amp, to try and eliminate the possibility of engine noise. You will however need to run switched power from the fuse panel (driver side kick), or tap into switched power directly off the vehicles ignition switch. DO NOT MISTAKE THE VSS WIRE FOR SWITCHED POWER ON THE FACTORY STEREO HARNESS.

Hope This Helps!

Jeremy's Car Audio Tips