SilberUrS6

the fscking archives, I got this regarding the changing out of our head unit for an aftermarket one. Comments welcome:

"Step by step instructions for replacing the Audi - Gamma factory radio with an aftermarket unit.

Disclaimer - This is for informational purposes only and is not guaranteed to be accurate. Proceed at your own risk and discretion.

I was very happy when I purchased my 95-A6 except for the radio. I didn't like the layout of the controls or that each bank of presets only holds 4 stations. The lack of a CD changer was also a big minus. I wanted to replace the factory Bose-Gamma radio with an aftermarket unit but was nervous. I've seen various posts that made it sound like it would be a major problem, especially when dealing with the Bose amplifiers. These steps are for the systems with the factory Bose option. I imagine that these steps would be very similar for the non-Bose option except that you would drive speakers directly from the new receivers power outputs. (The Bose has amps so you use the pre-amp outputs.)

I decided to go for it. It turned out to be a very easy conversion and would recommend it to anyone who posses mild skills and wants to upgrade their unit. The whole conversion took me about 2-hours but I did it without damaging any of the original factory wiring harnesses or connectors. This way I can pull the aftermarket stereo out and put the original Gamma back in. If I were willing to cut into the existing wires it would have taken half as long.

Items needed : Aftermarket receiver (standard DIN size) with pre-Amp outputs (4-Volt outpus recommended. 2&3 Volt outputs will work fine). Soldering iron, Solder, 3/16" inch miniature spade lugs (available at radio shack), Electrical tape, wax -paper, a hot glue gun, 4 nails, one RCA stereo patch-cord and an antenna adapter.

Step #1 - Removing the Gamma receiver.
Insert the 4 nails into the small holes in the corner of the unit. Push the nails in about 1.5" and when all 4 of them are in, stick your fingers in the cassette door and the unit will come out with a gentle pull.

Step #2 - Disconnect the Gamma receiver.
On back of the unit you will find 3 wiring connectors; a red one (top), a brown one (middle) and a black one at the bottom. Release the locking clasp and disconnect them. The brown one (middle) goes to the remote trunk-mount CD changer option. The red one goes to the speakers and the black one has the power connections. Pull off the grounding lug in the center of the unit and work the antenna connectors loose. They should both come out together so keep wiggling the entire assembly free. The Gamma receiver should now be completely free.

Step #3 - Create the wiring harness.
Cut the RCA stereo patch cord in half. You should now have 4 phono plugs and 4 signal wires. Strip these back a ways and pre-tin the leads. The ground wires (shields) can all be connected together and grounded as one. Solder the 3/16" mini spade lugs you got from radio-shack to the end of each of the patch cords. You should have 5 spade lugs attached to the 4 RCA phono plugs; right-front, right-rear, left-front, left-rear and one common ground.

You will also want to connect miniature spade lugs to the wiring harness that came with your new aftermarket stereo. Connect the spade lugs to the 1) Main power lead, 2) Switched (aux) power lead, 3) Ground wire, 4) Power antenna / Amplifier power lead and 5) (optional) Panel dimming lead that goes to the light switch.

These 3/16" spade lugs are a little large to fit into the wiring harness. Take a file and file down the spade lugs so they fit snug into the original harness connectors in the car. I would also recommend soldering the wires in these connectors to ensure they don't come out since many of the leads (RCA phono plugs for example) are very small and don't crimp properly.

Step #4 - Wiring up the audio connections
Cut a couple of 1X2" squares (technically rectangles) from the wax paper. Place the wax paper over the end of the wiring harness connectors in your cars dash and push the spade lugs `through' the wax paper as you make your connections.

The audio connections are all made on the RED connector. Place the wax paper over the connector and push the spade lugs attached to the RCA phono plugs through. Looking at the connector with the release clasp on your right, the pins are as follows:

Top row left - Left rear
Bottom row left - Left front
Top row 2nd from left - Right rear
Bottom row 2nd from left - Right rear
Bottom row 3rd from left (middle) - Common ground.

Step #5 - Connecting the power
Place the second sheet of wax paper over the BLACK power connector. Push the soldered lugs through the wax paper into the black connector. The pin wiring code is as follows:

Red wire - +12 volts switched by the ignition switch
White wire - Output to power antenna or amplifier
Gray + Blue wire - Connection to light switch
Thick Red+Blue wire - Constant +12 volts
Thick Brown wire - Ground (Ground to this and NOT the grounding lug you pulled off the middle of the Gamma receiver. They are not the same!)

Step #5 - Give it a test run
Don't put the unit in yet but give it a powered up test. Before powering up you may want to do a double check to make sure you got the wires right and that they are not shorting out. Connect the wires all up to the back of the new unit. This basically means plugging in the wiring harness, RCA phono jacks to the pre-amp outputs and the antenna. (You can skip the antenna for now and just play a CD). Turn on the car and make sure everything works. If it works continue on. Otherwise double check the wiring.

Step #6 - Make your own connectors
Right now you have about 10 wires just hanging on and ready to fall out or short against each other. To solve this we will make our own connectors. Cut a 6" piece of black electrical tape. Fold the wax paper between the wires and the connectors up; away from the factory connectors and towards you and the wires. Wrap the electrical tape so about ? of it sticks to the factory connectors and the other half covers up the wax paper. This should leave a small tub-like enclosure where your new wires are. Take a hot glue gun and fill this area with hot glue. The wax paper will prevent the glue from running down into the factory connector. The hot glue hardens fast, makes a good insulator and keeps all of the wires together. It's great for making cheap connectors. Make sure you glue up both the power and audio connectors.

Step #7 - Antenna
You will need an adapter to convert the weird Audi antennas to the "standard" antenna connector. Radio shack didn't have the part but Best-Buy did (ask the people in back who install the car stereos.) They told me that many Auto-Zone and Pep-Boy like stores also carry this. You can `snap' the existing antenna leads from the plastic case and tuck the other one out of the way. I used the black antenna lead. It shouldn't matter which one you use.

Step #8 - Put it all together.
Tuck the unused wires out of the way. Luckily the original Gamma unit is standard DIN size so your new unit should slide in neatly and provide a perfect fit. Enjoy your new receiver and CD-player !!!!"



Comments?

|skolnick

I tried the exact same thing and my speakers popped between tracks.

Hoog23

I replaced my radio w/another audi bose. Who knows how long it will last.

c4S6

But, doesn't seem to do it on my '95.5 with the direct plug.

Seemed like it wouldn't do it all the time, but when I had my '94, it would pop sometimes if I pushed the buttons too hard on the head unit and randomly at other times.

Zwoobah

mine does the same thing

SilberUrS6

But I have the head unit. I'm looking for comments on the actual how-to. Is it accurate? Can more be done?

Like one thing I thought of - how about finding a dead Delta and stealing the wiring from the back such that it plugs right up without doing spade lugs, etc?

|skolnick

A good stock system doesn't, but does when you try the above.

|skolnick

Some people have stopped the pop with blanking transistors or something. I say just rip it all out.

SilberUrS6

But the wallet had money to replace the failing HU, not the non-failing rest of the system.

Even then, the HU isn't failing - but the end is visible from here - it's got the "pop when you turn it off" ever 20th time it gets turned off.

If I ever sell the car, I want it to be returned to bone stock, so I have to have a working radio for that time. Pull it now, sez me.

|skolnick

good luck hombre. see you on the other side.