84' 928S 5 speed - disconnected the sensor to get at the fwd shifter cup and noticed after that the wires weren't colour coded =two white and one black- took a guess and hooked them up. Car starts and runs fine- what would I see/hear if the sensor was incorrectly connected.
BTW, replacing the fwd shifter cup is one PIA job - I'd say it's worth 1/2 of a motor mount R & R in frustration due to the poor access.

 

The same colour code should be apparent inside the black cable sheath at the base of the relay panel. IIRC, black is the sensor output and the two whites are the +12v and ground for the sensor heater. Easy to check - on a warm running engine, disconnect and the (black) signal wire should have an output of ~0.4v - or be swinging in the 0.2 - 0.8v range. The two whites will only show continuity/resistance - but no voltage.

 

The two white wires are the heater wires. It doesn't matter how you hook them back up. The black is the signal wire.

 

Mucho Gratias for the info. I have since driven about 25 K's and saw/heard nothing unusual.