I am wiring up a Kenwood Excelon 990 to a Honda harness. Coming out of the Kenwood is one orange/white wire labeled ILLUMI. In the manual it says wire this to the car dimmer. On the Honda harness there is solid orange wire labeled "illumination/dash light", and an orange/white labeled "dimmer". My question is what is the difference between these 2 wires and which is the correct one to use.

The reason I am asking is I just pulled this HU from a Ford Explorer I traded in. The Ford harness only had the orange/white wire and I connected the ILLUMI wire to that. The dimming feature of the HU never worked. Now it could be a faulty HU, but I do not know.

Please let me know which one to use for the Honda harness.

Thanks
Drew