This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your Porsche Boxster. The book contains 312 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 950+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website for more details.
There are three pedal switches on the Boxster, two on the clutch pedal and one on the brakes. The brake and clutch pedal switches get a lot of use, and they all have a tendency to fail once and a while. Replacement is really easy, and should take only about 30 minutes.
For the brake switch, the first step is to verify that your brake lamps are not working. If you're by yourself, then wait until nighttime and back up against a brick wall. You should see the reflection off of the wall when you step on the brakes - if you don't, then your switch is probably shot. It's important to note that the switch has redundancy built-in and the warning system should tell you when your switch is failing, but this doesn't always work.
The clutch pedal has two switches, although I'm not quite sure why. One switch controls the cruise control (turns it off when you push in the clutch), and the other won't let you start the car without the clutch pedal pushed in. If you're having intermittent starting problems with your car, I would look at this switch first.
Curious, but the cruise control switch is identical to the brake pedal switch except that the cruise control switch is red, and the brake pedal switch is a translucent brown. Both switches have three of the same the same part numbers printed on them.
The switches are relatively easy to access, as they are located right above the pedals. You will have to open the driver's side door and then stick your head into the foot well to see them. Replacement is easy: simply unplug the harness from the end and then twist to remove the switch. If you need to manhandle and/or break the switch to remove it, that's perfectly okay, since you will be replacing it with a new one very soon anyways. The clutch pedal switch that prevents the car from starting is a standard microswitch mounted with screws.
To finish the job, simply install the new switch into place, and reconnect the wire harness. Test the brake lights to make sure that they are working properly, and then reinstall the knee panel.
Here are the two clutch pedal switches. The yellow arrow points to the microswitch that prevents the car from starting if you don't have the pedal pushed in. The red switch is the one that deactivates the cruise control when you push the clutch in.
Here's a photo of the brake pedal switch (green arrow). Simply unplug the harness, twist the switch, and then remove it from the chassis. The lower left inset photo shows the brake and cruise control switches together. The only difference between these two is the color of the housing.