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.