So firstly I cannot take credit for my knowledge on how to do this I have merely done as instructed by a greater knowledge (RIP) and taken a few pics along the way to make a more idiot proof how to for numpties like myself.
The late AndyMac is entitled to full credit outlining the process here
I have a 2003 A4 and quickly learnt that my fancy new stereo wouldn't turn on due to the lack of an accessory feed. I went to a local car audio place and they put in a switched live feed, so the stereo would only be on when engine is on, but I'm sure like most there's quite a few times when your sitting waiting for something with music on, engine off.
What you need-
8mm ratchet.
scotch locks/piggy back links or soldering iron
wire
4 pin 12v relay (I bought this one) Mainly because I could pick it up that day.
4x female spade crimp terminals (or more solder)
Step one-
Remove the fuse cover using your key. Remove 3 8mm bolts, 1 is top left to the fuse box. then 2 are lower down the lower cowling below the service book holding slot. Once these 3 bolts are out the cowling will come away, use some pressure near the ignition barrel and the other side of the steering wheel to release the cowling. The diagnostics port easily unclips from the panel.
Step 2-
Remove the other 2 8mm bolts by the fuse box so this then becomes free. You then un hinge the back of the fuse board to get at the wires.
I used a multimeter to find a permanent live feed for the relays power.
Stripped a bit of the insulation back, then soldered in a similar thickness wire
Step 3-
To the left of the steering column there is some plastic trunking. Open it up (from the left hand side) and spread out the wires, you should find a little red wire.
Again I checked to make sure I had the right wire with my multimeter, stripped back some insulation and soldered in a similar thickness wire.
Step 4-
Run 2 wires from the back of the stereo area to the fuse box area. They should be similar thickness to the power feed wire from the fuse board. I have a black wire which goes to the ground of the stereo (there stereos harness will most likely have a black wire as ground. I had a red wire from the car audio shops work that goes to my stereos yellow switched live.
Sorry no pics of them
You should then have 4 wires flapping about by the fuse box.
So now either add crimped terminals to each wire to connect to the relay (easiest) or if you don't have crimps solder them to the relay as follows....
#30 Permanent 12v live in from fuse box
#85 Ground from black wire in stereo
#86 Switched source from steering column
#87 Switched live in to head unit
Insulation any solder joints/bare wire with some tape and cable tie any wires by moving parts to make sure they don't get caught up.
I then cable tied my relay above the fuse box-
Put your car back together and then you should be able to do this....
Thats right! Engine off and radio on, Hurray!
Please note, you follow my guide at your own risk and I take no responsibility for you screwing it up!
The late AndyMac is entitled to full credit outlining the process here
I have a 2003 A4 and quickly learnt that my fancy new stereo wouldn't turn on due to the lack of an accessory feed. I went to a local car audio place and they put in a switched live feed, so the stereo would only be on when engine is on, but I'm sure like most there's quite a few times when your sitting waiting for something with music on, engine off.
What you need-
8mm ratchet.
scotch locks/piggy back links or soldering iron
wire
4 pin 12v relay (I bought this one) Mainly because I could pick it up that day.
4x female spade crimp terminals (or more solder)
Step one-
Remove the fuse cover using your key. Remove 3 8mm bolts, 1 is top left to the fuse box. then 2 are lower down the lower cowling below the service book holding slot. Once these 3 bolts are out the cowling will come away, use some pressure near the ignition barrel and the other side of the steering wheel to release the cowling. The diagnostics port easily unclips from the panel.
Step 2-
Remove the other 2 8mm bolts by the fuse box so this then becomes free. You then un hinge the back of the fuse board to get at the wires.
I used a multimeter to find a permanent live feed for the relays power.
Stripped a bit of the insulation back, then soldered in a similar thickness wire
Step 3-
To the left of the steering column there is some plastic trunking. Open it up (from the left hand side) and spread out the wires, you should find a little red wire.
Again I checked to make sure I had the right wire with my multimeter, stripped back some insulation and soldered in a similar thickness wire.
Step 4-
Run 2 wires from the back of the stereo area to the fuse box area. They should be similar thickness to the power feed wire from the fuse board. I have a black wire which goes to the ground of the stereo (there stereos harness will most likely have a black wire as ground. I had a red wire from the car audio shops work that goes to my stereos yellow switched live.
Sorry no pics of them
You should then have 4 wires flapping about by the fuse box.
So now either add crimped terminals to each wire to connect to the relay (easiest) or if you don't have crimps solder them to the relay as follows....
#30 Permanent 12v live in from fuse box
#85 Ground from black wire in stereo
#86 Switched source from steering column
#87 Switched live in to head unit
Insulation any solder joints/bare wire with some tape and cable tie any wires by moving parts to make sure they don't get caught up.
I then cable tied my relay above the fuse box-
Put your car back together and then you should be able to do this....
Thats right! Engine off and radio on, Hurray!
Please note, you follow my guide at your own risk and I take no responsibility for you screwing it up!
