Lost backlighting on all dash switches

[AberdeenRTL]

Hello all,

I recently swapped out the factory radio (non-Navi) with a Kenwood DNX8120 and now none of my dash switches are backlit (the speedometer cluster is fine however). I'm not 100% sure this happened exactly at the time of installation as I haven't been driving at night much.

Here are the symptoms:
1) All the switches and knobs function properly.
2) The round HVAC display is lit brightly with the headlights off and goes completely dark with the headlights on (not sure if this used to be lit when the headlights were off?).
3) Aftermarket radio is bright with the headlights off and dims when the headlights are turned on (as expected).

What I have tried so far:
1) Pulled and inspected every fuse in all 3 fuse boxes.
2) Disconnected and reseated all 8 wiring harness clips behind the main dash panel (the only ones I touched during installation).

Any ideas on what else to try? I'm thinking of disconnecting the stereo and maybe even reconnecting the factory radio to see if that does anything.

Thanks for any ideas!

[BobP]

I don't recall if the instrument cluster is also affected, but isn't there a brightness control on the dash...to the left of the steering wheel I think.

[AberdeenRTL]

Thank you Bob - Yes, I tried that too. The brightness contol rheostat does adjust the cluster lighting correctly but doesn't turn on the backlighting for any of the switches or knobs (even when I rotate it past the "click").

[RidgeLI]

Possibly a bad ground wire?

RidgeLI

[MikeT]

Pull the dash apart again (As you would to replace the HU) and I think you'll find a loose connector that supplies the power for the dash lights.

[AberdeenRTL]

Found it. The aftermarket Scosche HA08B / HA08 harness connector has 2 orange wires coming out of it (one orange/white) but the Scoshe color code key only describes the solid orange one as for the "ILLUMINATION / DIMMER" (and no mention of the orange/white). The illumination wire from the Ridgeline factory harness is orange/white. In the confusion and against my better judgement I just connected both of the Scosche orange wires to the single Ridgeline orange/white wire. Apparently this grounds out all the dash lights because as soon as I cut away that solid orange wire everything came back on.

Thank you all for your quick suggestions. You minimally gave me the will to rip that dash apart one more time!

[shovelhd]

Nice find. Great HU choice, too.

[AberdeenRTL]

One last follow up on this - I should've cut away the orange/white wire instead of the solid orange one on the Scorsch adapter. I later noticed that the head unit wasn't dimming when I turned on the headlights. So now I have the Scorsch solid orange wire connected to the Kenwood DNX 8120's orange/white wire and all is well again. Lesson learned - don't use the orange/white wire on the Scorsch adapter!