Radio and lighting

[whozleft]

Before anyone asks, yes I did a forum search and found the following (except I inserted my radio info). I did not see a conclusion to this problem and was wondering if anyone has found a solution. The original post was in 2009. I have the exact same problem.

My original radio went bad and maybe I should have found a replacement factory unit instead of going aftermarket.


Thanks for any help!

Post from 2009
Replaced factory stereo in 2005 Pilot EX-L with aftermarket JVC KD-HDR70W. Now dimmer switch doesn't work and climatecontrol lights went out. Checked all fuses and nothing is blown so purchased light bulbs from Honda dealership to replace bulbs in climate control unit today and still nothing. Anybody out there have this issue or knows what else can be wrong?

[toml]

There are two lighting-related wires in the harness. One indicates when the headlights or 'parking' lights are on, and the other which feeds a variable voltage for adjusting the brightness of the dash lights.

For pretty much any aftermarket hard unit, you want to connect the 'headlight' wire to the radio's 'lighting' wire so it dims whenever your headlights are on. It took a call to Crutchfield for me to get this straight, as the diagrams refer to the other wire as "dimmer" and you would think that would be the one to attach to the radio.

I'm wondering if the other wire may have been attached to your head unit and that may be causing the issues you are seeing with your dash lights. It's a long shot, but worth a look.

[3rdrow]

are you sure the harnesses for the climate control unit are plugged in?

[whozleft]

Toml
Are you saying the wire marked "dimmer" from the new head unit wouldn't be used at all then? I will look at it this weekend and appreciate your input. I will let you know what I find out.

Thanks a bunch.

[toml]

Originally Posted by whozleft

Are you saying the wire marked "dimmer" from the new head unit wouldn't be used at all then?

In the case of the wiring for my 2008, the Metra adapter wiring diagram refers to the two wires on the Pilot side as 'Illumination' (orange) and 'Dimmer' (orange/white). It is the 'Illumination' wire that connects to the head unit. The 'Dimmer' wire from the car side ends up not being connected to the head unit.

So whatever the manufacturer calls the wire that controls lighting on your head unit, that would be connected to the 'Illumination' line on the car side of the connection.

If you have a meter, you can check the two leads to verify - the one you want to connect will just go on and off with the headlights. The dimmer line will vary voltage according to the setting of the dash light dimmer adjustment.

What made this even more counter-intuitive for me was that in my case the color of the wire on the Pioneer head unit side was actually orange/white. So you would naturally assume that goes to the orange/white on the adapter harness, but it really goes to solid orange. (Pioneer labels this wire 'connect to lighting switch terminal', so at least they didn't call it 'dimmer'.)

I suppose there may be some aftermarket head unit somewhere that actually uses the dimmer line (or even both), but the Crutchfield tech said pretty much none do these days.