Illumination or Dimmer wire to radio?

Hello. I have a 2002 Toyota Tacoma PreRunner and purchased a Pioneer AVIC-X930BT radio to replace the factory radio. I also purchased a Metra #70-1761 wire harness to make the installation easier (it simply plugs into the factory plugs and then the wires are connected to the harness that came with the radio). All the wire colors map easily and found a small wiring chart for Toyota 1987 and up.

http://www.installdr.com/Harnesses/Toyota-Wiring.pdf

However, I am having difficulty with one wire that is on the radio harness. The wire is an Orange/White wire that is labeled on the Pioneer to be connected to the "to lighting switch terminal." My Metra harness has a Orange/Black and Orange/White wire. The Orange/White is listed as a "Dimmer" wire and the Orange/Black is NOT listed. Instead they list an Orange wire as an "Illumination" wire, which is not on the harness. Interesting enough is that the location of these orange wires on the Metra Harness are in locations that are indicated as "do no use" in this wiring diagram. I feel that the diagram is not completely correct because when I turn on my headlights, there ARE some lights that turn on in the radio (around the volume knob and behind the buttons).

I would really like to connect this wire (rather than leaving it unconnected) as the Pioneer radio as a dimming (day/night mode) function. Such that when I turn on my headlights, it goes into a "night mode" so it's not so bright.

I've contacted Metra for some assistance and they say that the Orange/White wire on their harness is mostly likely connecting to the wire coming from the dimmer switch for my dashboard lighting. Therefore, if I connect that wire to the Orange/White on my radio, the radio display may begin to flicker and turn off. That makes sense and I have verified that if I dim the dashboard lights, the radio lights dim as well. But they can't tell me if I should use the Orange/Black wire instead. I think I should be able to use one of these and I never mess with the dimmer switch anyway (it's always all the way up).

Does anyone have any information on hooking up a radio (such as a Pioneer D3, X930BT, or similar) that may have run into this? I'm wondering if this wire to the radio needs to be a positive (+12V) or ground? The manual does not say and I can't find a good wiring diagram for my 2002 Tacoma to find where else I could grab if my headlights are on/off (without the dimmer being involved).

If I can't use either of the orange wires on this harness to connect to the radio, does anyone know where I can tap into to get when my headlights are turned on/off?

Thank you very much for your time.

Best Regards,

DataCrypt

 

Hey man, I'm having the same exact situation installing a pioneer headunit with a Metra harness now. I know it was a long time ago, but do you happen to recall a solution? Cheers

 

Are you 100% sure the head unit you bought is capable of dimming? Some do and some dont, thats why I ask.

 

It's not installed yet so I'm not 100% but according to the pioneer website it has a dimmer on/off setting so I believe it does

 

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