Vehicle Power Mirror Autofold

Hi Guys

I am attempting something that is above electronics level but i am willing to learn. I also hope to receive positive feedback as i know most automotive topics gets shut down quickly and frowned upon

My vehicle has power mirrors, but i have to switch the button on the dash to have them collapse or extend. I want to make this process automated with my central locking.

I attach a picture of the wiring diagram, here i marked the red star is where the ignition switched 12V+ comes into the circuit, then at the black start is where the GND exits. where the green star is where the manual switch is, it acts like a DPDT switch basically, switching the GND and 12V+ around to make the mirror motors collaps or extend.

I have the following in mind:

DPDT relay exactly where i have the green line drawn, this, when the relay is powered by IGN 12V+ it will keep the circuit basically the same and while driving the vehicle and pressing the manual button will still collapse the mirrors, if IGN 12V+ is turned off the relay must switch to normally open off state and will wait for an input from the arduino. the arduino must sit and wait for a pulse from the central locking motor to then collapse the mirrors and extend the mirrors when unlocked.

Am i on the right path? Will the arduino be powered 24/7 causing too much power draw leading to a flat battery? is there any experts that is willing to help me in the right direction?

Image from Original Post so we don't have to download it. See this Simple Image Guide


Can you check whether the motors have limit switches incorporated? This would simplify the required circuit, down to a simple DPDT relay powered by the ignition control signal.

The check is simple: make a motor reach its limit, and check the consumed current. If it increases at the end stop, no limit switch is incorporated, otherwise the current should drop to zero then.

Robin2, thank you for posting that image, makes it alot easier and noted the "how to guide" thank you very much.

DrDiettrich, i will take a closer look at the end stops, but from testing i have noticed the 2 wires called YE-GN and BU that goes to the motor simply swaps polarity when the button is pressed/depressed. In normal state the YE-GN will be 12v+ and BU ground, if button is pressed (it toggles, not momentary) YE-GN will be ground and BU will be 12v+.

Unfortunately the IGN method is good, i had a working circuit for that but i specifically want it to open/close when locking/unlocking vehicle

Two tasks: find the signal(s) telling lock/unlock, and determine how the mirrors can be extended/collapsed safely (time, end state?).