awdsvx discovered (and posted in
this other thread) that Scosche's reverse harness lacks the orange/white illumination wire; it only has the plain orange wire. The 2002 WRX changer needs both for the illumination to work correctly.
awdsvx bought a second Scosche reverse harness and transplanted its orange wire into the empty slot on his first reverse harness.
Before doing that, I'd suggest checking for harnesses made by the other manufacturers, Metra and American International, to see if they have reverse WRX harnesses with both orange wires (14 wires total).
[Update: None of them does, currently. I'm going to start making some in limited quantities, and will continue making them if there's enough demand or until one of the harness manufacturers makes one with all 14 wires. Watch the "Wanted or For Sale" forum for details.]
The pinout for the 2002 WRX harness is here:
[Deleted; see edit below]. Note that even though pin 14 is shown as a "no connection," the WRX
radio actually provides the amplifier remote power-on signal on that pin (which the SVX can use for the power antenna -- it will extend any time the WRX radio is on, even if you're listening to CDs). The WRX itself has neither a power antenna or an external amplifier, so this pin has no connection in the car itself.
[Correction- it's the power antenna control, not amplifier power-on; see the reply below]
[Another correction- Recent model WRX's now have an antenna amplifier under the rear deck because they only have a foil antenna on the rear window; so they do now use pin 14]
[Yet another edit: I created a better pin-out for the WRX harness. All Subarus from 1993-up except the SVX use this same pin-out]