This article is one in a series that have been released in conjunction with Wayne's book, 101 Projects for Your Porsche 911. The book contains 240 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Porsche 911 owner's collection. See The Official Book Website for more details.
Drivin' a swank Porsche ain't nuthin if you don't got no tunes! Nuff said, there comes the time when most people want to upgrade the stereo that came in their 911. If your car and radio are really old, then no doubt you are torn between leaving the factory radio installed, and installing a new top of the line CD player. It's always been my contention that the car should be for enjoyment while you're driving: thus install the new stereo. On the other hand you can opt to do what I did in my 356: leave the original Blaupunkt radio installed in the dash, and place a new model hidden away inside the glove box.
Designing and implementing a new stereo system in your 911 can be a daunting task, if not an art. For the purpose of simplicity, we'll assume that you only want to replace the head unit in your car. Any car audio aficionado will let you know there are hundreds of options that you can install, including the addition of amplifiers, bridges, subwoofers, tweeters, and CD changers. Most people reading this project would probably be happy with a newer CD player in their car, so we'll stick to that.
The first step in this procedure is of course to obtain the stereo. The Porsche 911 has always used the standard car stereo form factor that has pretty much become commonplace for the last few decades. Most units nowadays support four speakers, and don't need external amplifiers, so any basic off-the shelf unit should suffice.
There are two main parts to the installation of the stereo: the physical installation of the unit inside the car, and the electrical hookup of all the connections. Either one of these tasks may be made easier or harder by the stereo that you have in your car right now. If the unit that is currently installed is properly connected and is easy to remove, then the new installation shouldn't be too difficult. Make sure that you disconnect the battery from the car before you start working on the electrical connections.
The old stereo obviously needs to be removed before the new one can be installed. Depending upon how it was originally installed, this could be the most difficult step of the entire process. In general, car stereos are designed to be very difficult to remove, in order to discourage theft. If the unit that is installed is a pull-out unit, where the entire machine can be removed from the dash, then the task will be easy since you can access all of the mounting points simply by removing the stereo. However, if the unit doesn't pull out by itself, it may require several hours of work to try to remove it.
Car stereos usually ship with a mounting sleeve that you mount securely inside the car, and then slide the stereo into. These sleeves have special angled metal tabs that you bend and twist to make sure that the sleeve or bracket is securely installed in the dash. The sleeves usually have a minimal amount of screws and bolts, and instead rely mostly on these tabs to secure the main unit.
Once the mounting sleeve is properly installed and secured in the dash, the main unit is slid into the sleeve. Small, spring-loaded locks usually snap the main unit into place. It is these snaps that make the unit very difficult to remove. It is almost impossible to access the mounting points for the mounting sleeve with the main unit installed. It's also nearly impossible to remove the main unit once it is installed into the dash. Hence the difficulty for both the potential stereo thief, and the fellow trying to install the new radio.
One rule of thumb to follow is to make sure that you double-check your work, and don't accidentally install the stereo incorrectly. Because of the nature of the sleeve-mount design, fixing your mistakes will be very difficult. Unfortunately, a lot of damage can occur to the both the stereo and the mounting hardware when you are removing it, so if you mess-up you might end up destroying your brackets. Make sure that you follow the instructions that came with the stereo: there aren't really any specific mounting instructions that pertain only to the 911.
If you car has the original stereo installed in it from a long time ago, then it may be easier to remove. Some of the real early stereos were simply bolted into the dashboard, without much thought as to theft-prevention. A quick look under the dashboard should confirm this.
The second part of the installation involves the wiring of the stereo. Each 911 has been wired slightly different from year to year, so the best method for figuring out what each wire connects to is to check where the wires to the previous unit were connected, trial and error, or by checking the electrical diagram for your year car.
In general, new stereos will have the following connections that will need to be hooked up to your 911:
Left and Right Front Speakers. Very often, previous owners will install speakers in the doors, or more pairs of speakers throughout the car. The best bet is to look at how the previous speakers were connected, and then tap into those lines. For early 911s with the large center speaker, you should connect both the left and right speaker channels together and connect them to the speaker. Check the manual of the stereo to make sure that this will not create an impedance imbalance and damage the stereo. Make sure that your speaker connections (positive/negative) are connected properly. In most cases, it won't make a difference, but with some stereos it does matter.
Left and Right Rear Speakers. Again, the best bet for wiring these is to check how they were connected previously.
Continuous Power. This is the lead from the starter switch that is always turned on. This power lead is considered 'hot' 100% of the time, even when the car is sitting in the garage. The power supplied by this line makes sure that the clock and any memory functions of the stereo are retained when the ignition is off. On most 911s, this line exits out of the ignition switch and is colored yellow. Double check this with a multitester before tapping into it.
Switched Power. This power line is 'hot' only when the ignition is turned on. If you wish to have your radio operational even when the ignition is off, connect this line to the continuous power line. This line also exits out of the ignition switch and is usually colored red. Again, double check before you tap the line.
Antenna Connection. The antenna should have an RF connector on it that plugs into the back of the radio. This is a standard connector, and every car and radio should have matching connectors and receptacles.
Power Antenna Switch. If your car has a power antenna, then it will need a signal from the radio to indicate that the radio has indeed been turned on. If your radio doesn't have one of these switches, then you can connect the power line for the antenna to the switched power line. This of course, means that your antenna will be up anytime that your ignition is on.
Ground. Make sure that you connect this to a nearby spot on the chassis. It's usually wise to use one of the nuts or bolts that mount the radio to the chassis.
It's also a wise idea to place a small fuse in the lines that power the radio. For the most part, either the continuous power or switched power line will carry most of the current. Find out which from the stereo installation instructions and install a small fuse in this line if the stereo didn't come with one already.
Most new stereos come with a mounting bracket that is to be installed into the dashboard of the car, and secured with mounting tabs. The stereo then slides into this bracket, and can't be easily removed. This, of course, is to prevent theft, but can be a huge pain if you make a mistake while installing the unit.
The newly installed stereo will not only sound better, but it will give your car an updated look that brings it into the 21st century. No more AM/FM radios or 8-tracks here!