1994 dodge ram 1500 dash dimmer wire

The stereo im installing has illumination wire ( orange ). Wiring diagram for truck says no illumination wire but there is a dimmer wire ( ORANGE / white ) I believe. Do I wire them together for stereo to dim with dash lights?

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Bowtiemob

i assume you are using a wiring harness to install the radio but a lot of them are universal for a few different years and models so the plug will have extra wires that if you look on the vehicle side of the plug there will be no wire on the actual trucks plug. personally i would just leave it alone but you can hook it up if you want.

A true illumination wire has 12 volts when the parking lights are turned on.   A dimmer wire also has voltage when the parking lights are turned on, but it varies with the dimmer switch--as you turn the dimmer switch down, the voltage on the wire gets lower.

The head unit's illumination wire is meant to dim the display when you turn on the lights--it's just looking for the voltage. A dimmer wire will work for this connection in place of a true illumination wire, provided you keep the dimmer switch turned up. If you turn the dimmer down, the voltage will drop out and the head unit will go back to the bright setting. If you keep the dimmer switch in the middle, it may or may not work, depending on how much voltage is required to trigger the head unit's dim feature.

Many head units have settings that allow you to override the illumination function. If yours has this option, you can go ahead and connect the illumination wire to the vehicle's dimmer wire. If it doesn't work the way you want, you can just turn the feature off in the head unit settings.