Hello everyone, I'm trying to help a friend with his QX4...
He says that when the headlights are off, the instrument lights are on... and when he turns the headlights on, the instrument lights won't come on. Someone else had asked about it here, but recieved no answer... but I'll try anyway.

Anybody hear of this? Or since he has electrical knowledge, should he try to just rig up a relay bypassing the stock wiring?

has the car ever been serviced for electrical issues? If so, chances of having the wires connected in the incorrect terminal is high. If you can get a wiring diagram, that can definately determine the cause. Based on issues similar to this on construction equipment, we always found wires incorrectly routed. See if this is the issue...

When the headlights come on the dash lights dim, there should be an adjustment for the dash lights on the left side of the dash. It could be that it's turned down all the way.