I have an old Nutone LS-100 (circa 2000) which needs replacement. I noticed that the power connector for the fan unit is a 6pin Molex, which surprised me. This is only an exhaust fan and has no light / need for a secondary circuit. Any idea as to what the extra pins are for?

My more modern bathroom exhaust fans are 3pin (hot, neutral, ground), so wondering what the extra pins are for.

I have not gone up into the attic (hard to access) to discover whether there is anything special in the wiring into the enclosure.

  • 4
    It's like a car dashboard with some blanks for options you didn't pony up for.
    – dandavis
    Commented Oct 27, 2021 at 20:13

2 Answers 2


Most companies produce a wide array of fan/light/heat/nightlight combos. It's probably a cost/production efficiency to use the same connector for all of them, and it's probably more likely than not that some are unused.


If you buy a fan from a major manufacturer, it is very likely that they sell 3-6 versions of the same model of fan.

  • different styles of motor
  • light kit or not
  • secondary light kit (night light)
  • sensors

What I am getting at here is the electrical "circuit board" is probably the same for all of them. This allows them to manufacturer these cheaper and allows them to sell you upgrades.

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