Does the LEGO "Power Functions Extension Wire" (8886) work in both directions between old 9V and new Power Functions devices? Here is the LEGO "LEGO® Power Functions Extension Wire" (8886):



We can see that the left connector can connect to old 9V electric bricks or wires and the right connector can be plugged to the new Power Functions connectors.

The LEGO website gives this description:


  Power up your LEGO® Power Functions creations with this 8" extension
  wire. Make your models bigger, better, and more mechanized than ever
  before!
  
  
  Allows you to connect your LEGO 9V electric systems to the new Power Functions!
  Extension Wire is 8" (20cm) long
  


(emphasis mine)

Does this cable work in both directions?


Can it power a new Power Functions motor from an old battery box?
Can it power an old motor from a new Power Functions battery box?


Do switches like the old one or new one let you control new and old motors respectively?
According to Customer reviews on the official website, this cable enable powering motors in both ways between old and new power functions versions:




  This cable allows you to power the new 9v motors from the old 9v system or vise versa..


Author: heavyD.



But there is an incompatibility between the old battery boxes and the IR receivers:


  This cable also powers new motors from the old battery box, but it cannot power an IR receiver, which requires the new battery box and all 4 wires of the new cable. (This cable only converts the 2 motor-powering wires.)


Author: Technic010.