dimmer input wire on alpine nav

This is probably the wire that dims your screen when you turn on your headlights. This is useful so the screen is not blinding at night times! You want to connect that wire to any wire that is 12v+ when your headlights are on. What kind of car are you installing to? I believe most cars have a dimmer wire on the harness already.

no, the dimmer wire is for the knob that controls the brightness of instrument  lights in your vehicle,Aaron

united kingdom eh? you guys have wierd sizing for your headunits and stuff dont you?Aaron

there is usually a illumination wire with your factory radio wires. connect the blue/white wire to that wire. this is to dim your headunit screen when u turn on the parking lights/headlights

The dimmer,or just a parking light wire will both accomplish what it wants,those units usually just flip from dim,to bright,as far as the wire is concerned. the pioneer 7500 has a light sensor that progressively dims the screen,but still uses the dimmer wire(others may sense as well,but i put in 4 of those for 1 of anything else anyway..)..only very old units actually 'dim' (based on voltage;progressively anyway..(that I have seen))'Stereo' Mike

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