Tech Article Title Author Date
Radar Detector Hardwire with the Homelink Visor WCS 2002

If you purchased the Convenience Package with your Audi, you have a built-in power source for your radar detector literally inches from it's visor mount point. If you don't want to endure the direct-to-fusebox method of install, this solution is a simple and time effective alternative. The Homelink power is off when the ignition is off for two good reasons: child safety and home security. Naturally, this power mode is preferred for the radar detector as well. The fuse for the Homelink runs 5 amps which is more than enough to feed both the detector and the Homelink system.

There are three methods of bridging the wires to the Homelink system; soldering the leads right to the back of the Homelink plug (quick and dirty), stripping the sheathing off of the Homelink wires and T-boning them or the solderless in-line (22-24 AWG) bridging clips you can find at any auto parts store (more elegant but a tight fit).

You don't need much in the way of tools, just a small slotted screwdriver for prying, a regular sized Phillips head screwdriver for one screw, a continuity/voltage tester, wire strippers, a small strip of electrical tape, a small soldering iron (that includes solder) and about 30 minutes of time. The in-line solderless bridging clips are optional and will require needle nose or regular pliers.

Measure Fit, Remove Visor and Homelink Cover:

First things first! With ignition OFF, Get your radar detector and put it up on the visor to it's new home. Now take either a length of string or your connecting cord (straight cord is better than the coiled variety, either will work) and measure it from the power in of the detector to the point closest to the bottom left of the Homelink cover. Route it the way it will be finished. Be sure to run the wire between the visor and the top back (windshield side) of the radar detector since most detectors have an eye on top that looks back out your rear window for radar signals. Add two (2") inches to this measurement and cut and strip your cord so you have around 3/8" of exposed wire on the exposed ends. Twist the end strands tight and set aside along with the detector.

Using a small slotted screwdriver, gently remove the plastic screw-hiding insert from the mounting point for the visor. You'll see a small indentation in the visor mount bracket, that's where you insert the screwdriver to lever the small 1/4" diameter disc out. Next, use the Phillips head screwdriver to remove the visor retaining screw. Once the screw is removed draw the visor out of the headliner using a curved motion to accommodate it's semi-circular shape. To keep the visor from falling into your lap, keep the right side of the visor partially engaged to the headliner clip until your ready to remove it.

You'll see two plugs, gently pull them apart using both hands; one is for the vanity mirror power and the other for the Homelink power. Don't worry about which one is which, Audi has differentiated them for you by length and by connection type and they only plug in one way so there's no polarity problem when re-connecting.

Now take your visor to a convenient work area and use your screwdriver to gently work around all sides of the Homelink cover, prying up on the cover bit by bit until it comes off. If you are afraid of damaging the goods with your screwdriver, that plastic spatula you turn your pancakes with can also be used to good effect.

Removing Unit and Bridging Wires:

Once the cover is removed, you'll see a piece of metallic adhesive tape that secures the body of the Homelink unit to the visor. Peel this back from right to left and don't touch the adhesive backed side. The Homelink unit now can be removed by rocking it out of it's cradle. You'll see a white plastic plug at one end, use both hands to wiggle and gently separate the unit from it's connector and place to the side.

The Homelink connector has two wires feeding it, the brown wire is 12 volt negative and the black wire is 12 volt positive. Radar detectors use the center pin (usually) for positive (red) and the outer part for negative (black), make sure of detector color polarity by testing it or refer to the manual. The plastic feed connector coming from the visor doesn't have much wiggle room but you can flip it over to reveal the rear feeds.

You can strip some sheathing from the black and brown wires (a 1/4" will do) and T-bone the new wires on by wrapping then soldering the leads together; red detector wire to black Homelink wire (positive), black detector wire to brown Homelink wire (negative); finish by wrapping with electrical tape. The other method is to use small solderless bridging clips but there isn't much room to fit them in between the connector and the visor. You can also solder the tips of the detector wires right to metal pins inside of the Homelink connector by laying the individual detector power feeds one by one on top of the metal pins and briefly soldering them. If you do this, place the solder
on the hot iron first instead needing three hands to hold three things simultaneously.

Once connected, use your VOM/Continuity tester to verify that the connections are good.

Wrap Up:

By now you should have the radar detector wires firmly attached, one way or the other, to the back side of the Homelink connector. You shouldn't have too much trouble re-assembling the pieces, just reverse the disassembly process. Let the new power feed for the detector fit in-between the visor and Homelink Cover or you can always take a small rattail file to the cover for a more exacting fit.