I have a +4 which had the wings off and the paint shop muddled the connectors up. Basically there were two wires for the non existent wing top lights. Took me a while with a multimeter identifying which wire was connected to headlamp dipped bulb and matching that with the wire that went live when the dipped beam switch was activated. Don't know if the loom for the Aero also had these redundant wires.
Hope this helps.
