According to page 33 of the [D3200 Reference Manual][1], the light you see is functioning as the *self-timer lamp*, not as the *AF-assist illuminator*. The manual includes no instructions as to how this feature might be disabled.

One possible workaround might be to use an [MC-DC2 Remote Release Cord (1 Meter)][2] wired cable release instead of the wireless remote.


  [1]: http://cdn-10.nikon-cdn.com/pdf/manuals/dslr/D3200_EN.pdf
  [2]: http://www.amazon.com/Nikon-25395-MC-DC2-Remote-Release/dp/B001F6TXME