What is the ILL wire for?

And where to connect the ILL wire on an Android Headunit?

What is the ILL orange wire for and will the Android headunit still work if the ILL wire is not connected?

Universal-fit Android headunits, just like our favorite double din, are designed to fit various vehicles with various custom connectors. The main connectors on an Android headunit are the two universal ISO connectors, and the two ISO connectors appear on universal Android headunits and many older vehicles. For newer vehicles with custom connectors, an ISO adaptor converts the manufacturer’s custom plugs to the ISO standard.

ISO doesn’t have an ILL wire

ISO doesn’t cover some of the extra features your Android headunit can use if they are provided by the vehicle. The Android headunit may have some extra wires, and one of these is the ILL wire. Often the ILL wire is an orange wire on an Android headunit, but not always. The best thing to refer to is the markings on the wire for ‘ILL.’ There is also a guide supplied that should show which color lead is ILL.

It will still work if you don’t connect the ILL wire to the Android headunit. But you will be missing one useful feature for an Android headunit, so it is well worth tracking down the best place to connect it.

ILL is for Illumination

The orange wire in our picture is labeled ‘ILL’ for ‘illumination.’ The wire signals the headunit to change some of its settings. Typically illumination signal dims the android headunits backlight display or alters the button light brightness.

Have you noticed your vehicle dashboard lights dim when the headlights are on? It makes the dashboard lights less distracting to the driver when it’s dark. The android Headunit orange wire can connect to any lights in buttons or switches that dim like this. Ideally, the factory headunit you are replacing also has the orange ‘illumination’ wire, and your orange android headunit wire can be connected to this instead.

Always ILL

ILL is always for Illumination, but the wire color is not standardized. You may find your Android headunit has an ILL wire that is not orange, which doesn’t matter. As long as you treat ILL as Illumination, it will work.

Check before connecting, if you are not sure.

Check the wires before connecting them! But tracking down a switch that is illuminated will reveal an illumination wire. Use a 12v meter to earth to find the wire that changes state when the button lights go on/off with the headlights; you will then find where to connect the orange wire on an Android headunit.

ILL wire on Android Headunit car stereo
ILL wire can be a concern when installing an Android Headunit

Other wires in the same series

Wires in the speaker connections series

I am an android-headunits.com staff blogger. I have been using Android on my devices for many years and have learned a lot about the features and best hardware to keep up with the latest Android versions. I also make the coffee ☕

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  1. Thanks!!! I’ve been looking for the descriptions of these wires on this new DIN-1 unit for my car. You, my friend are a gold mine of information. Thanks for sharing, you are truly a blessing.


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