Audi A4 2007 - Radio resets when turning over

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Mon 17 Apr 2017 10:58
Audi A4 2007 - Radio resets when turning over - Mark G123

I have an aftermarket radio, I'm pretty sure it's wired correctly, as under normal situations it remembers all its presets when left. However on occasion when turning the car over, it will reboot and lose all its presets.

I am thinking a large voltage drop is causing this. The battery is pretty new (18 months old). Is there something I should be looking at for other causes?

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Mon 17 Apr 2017 11:07
Audi A4 2007 - Radio resets when turning over - Peter.N.

You possibly have a poor connection on the battery or earth, do the lights go very dim when you engage the starter? The only way you can positively check is to connect a meter across the radio 12v input and check the voltage when cranking.

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Mon 17 Apr 2017 11:07
Audi A4 2007 - Radio resets when turning over - Railroad.

You should have two separate 12v feeds to the radio. One will be permanent and one will be from the ignition switch auxiliary position. Make sure they're not the wrong way around at the radio unit.

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Mon 17 Apr 2017 11:17
Audi A4 2007 - Radio resets when turning over - Mark G123

I assumed if the were reversed, the radio would forget it settings wherever the ignition is off. Is this not the case?

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Mon 17 Apr 2017 15:15
Audi A4 2007 - Radio resets when turning over - elekie&a/c doctor

The battery would have to be very low for the radio to forget its memory,and I think the engine would struggle to start.A factory radio system does not have an auxillary power supply system and switches on via the Can network.So if a non standard radio has been fitted,I would suspect an additional can power converter has been installed.You would need to remove the radio to confirm any add-on box to the power lead.

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Mon 17 Apr 2017 15:27
Audi A4 2007 - Radio resets when turning over - Mark G123

The radio is fitted using a 3rd party kit.

www.dynamicsounds.co.uk/audi-a4-2007-double-din-ca...l

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Tue 18 Apr 2017 10:58
Audi A4 2007 - Radio resets when turning over - Peter.N.

As mentioned there will be two 12v feeds, one permenantly live and one ignition switched, on most after market radios there is provision to swap these round, if you have them round the wrong way you will loose the memory when you switch the ignition off but I can't see why that should happen only when the voltage is low.

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