I have a 2009 Focus Zeetec Diesel. I have an aftermarket stereo that, surprise surprise I have had to swap the yellow and red wires. There is a canbus involved but after swapping those wires, I can’t get the memory to stay. I had to swap as the stereo drained my battery. It now comes on and off by ignition but I need to get the memory sorted

By changing the red and yellow wires you put an ignition switched 12 Volt power onto the circuit that requires a permanent 12 Volt power for the memory.

The only way to solve the memory issue is by changing the red and yellow wire back. This however takes you back where you started.


What type of audio system do you have? In case of a Chinese Android audio system, I suggest replacing it with something better quality.

Put the wires back the correct way.

Install in series with each wire a Diode (make sure to fit them the correct way around), something like the 1N5401

The problem you are having with your Chinese stereo is that the permanent live feed is back feeding through the ignition live wire when the car is switch off.

On my Android head unit I had it all wired in but it was keeping the canbus awake and you couldn’t lock the car. I’d missed something in the instructions about disconnecting one of the wires. Can’t remember colour etc but it had its own single terminal connector you could disconnect as opposed to having to pull it out of a plug etc. if you’ve got similar in your wiring it’d be worth a try