What is the ILL wire for?

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

Universal fit android headunits, just like our favourite double din are designed to fit a variety of vehicles that have various custom connectors. The main connectors on an android headunit are the two universal ISO connectors. The two ISO connectors appear on universal android headunits and many older vehicles. For newer vehicles with custom connectors there is an ISO adaptor to convert manufacturers 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 and 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 colour lead is ILL.

If you don’t connect the ILL wire on the android headunit it will still work. 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 to.

ILL is for Illumination

The orange wire in our picture is labelled ‘ILL’ for ‘illumination’. It is the wire that signals the headunit to change some of it’s 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 is to make the dashboard lights less distracting to the driver when its dark. The Android Headunit orange wire can connect to any of the lights in any of the 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 colour is not standardised. You may find your android headunit has ILL wire that is not orange. This 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, you will then find where to connect the orange wire on an android headunit.

ILL wire on android headunit
ILL wire can be a concern when installing an Android Headunit

Other wires in the same series

Wires in the speaker connections series

An android-headunits.com staff blogger. I am a multi-skilled dogs-body and 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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