I was going to hard wire power to my radar detector following the instructions in Robert Leidy’s Power for your Radar Detector article. I decided at the same time I would add a pushbutton to my dash to activate my garage door opener. I was tired of having a big remote taking up space in my Z3.
What you will need:
Garage door opener you don’t mind taking apart
Momentary pushbutton switch (I used Radio Shack #275-644 because it fit with the interior of the Z3 nicely)
Wire (I used 20-gauge stranded wire)
Drill or Dremel-type tool
Solder and soldering iron (optional but highly recommended)
Electrical tape
Phillips screwdriver
First, take your garage door opener apart and figure out how the button on the outside of it activates the switch inside. You should be able to activate the opener by bypassing the switch with a piece of wire. Verify you can do this by using a short piece of wire to touch the contacts at either side of the switch, and see if it activates your garage door.
Second, follow Richard Carlson’s Cutting the Cord article and Robert Leidy’s Power for your Radar Detector article to remove the plastic plate over the pedals and also the one under the steering wheel. You don’t want to solder a switch to your garage door opener or drill a hole in a dash panel until you know you can take all the appropriate pieces apart, and also that you can bypass the switch in your garage door opener.
On U.S.-spec Z3s, to the right of the steering wheel there is a little blank plate in the same position that there is the fog light switch to the left of the steering wheel. Use your fingernail, pocketknife, or thin-bladed screwdriver to pop this out–it should come out easily.
Using a drill or a Dremel tool, drill a hole in the center of it. Note that I did not have a vise–if you drill it and hold it by hand like I did, be very careful!
Then, use a cone-shaped sanding bit to slowly enlarge the hole until the switch will fit through it. Note that the switch has a back piece that screws on to it. You push the switch through the hole from the front, and then screw the back piece on to secure the switch in the hole.
For the next step, you may leave the switch in the little plastic panel or you may take it back out if you are afraid of melting the panel with the soldering iron.
Cut two 3-feet long pieces of wire and strip about a half-inch from each end. Loop one end of one of the pieces of wire through the little hole in one of the leads coming out of the switch. Solder the wire in place. Repeat with one end of the other piece of wire. Just to be safe, wrap electrical tape around both soldered connections.
If you removed the switch from the plastic plate for the above step, it is now time to feed the wires through the hole in the switch and to fasten the switch to the plate. Now, feed the wires through the hole in your dash out of which you popped the panel. You should be able to push the panel and switch into place flush with the dash for a clean “factory” appearance. You now have the two 3-feet long pieces of wire hanging down below the dash.
Be very careful at this point. It is good if you have a helper too. Sit in the driver’s seat of the car with some sort of tray or disposable plate in your lap. You will be soldering the wires to your garage door remote in your lap in a moment, and you don’t want to take any chance of burning yourself or your Z3. Before permanently attaching the wires to your remote, hold each wire on the contacts on either side of the internal switch in your garage door opener, and ask your helper to push the button in the dash. If everything is connected correctly, your garage door should be activated.
You will have to decide the best way to affix the wires to the contacts in your remote. For me, the best way was to solder them to the bottom of the remote circuit board on either side of where the garage door remote switch was. Be careful not to melt the circuit board with the soldering iron. Also be careful not to bridge any contacts with melted solder, thereby causing the garage door opener to be active 100% of the time!
After permanently affixing the wires to the garage door opener, again verify that the pushbutton in the dash will operate your garage door. Then, use electrical tape to secure the garage door opener somewhere under your dash, keeping in mind that you will need to reinstall all plastic panels which you removed.
Finally, reassemble your dash, admire the clean “factory” look of the button you installed, and drink a celebratory beverage to congratulate yourself.








