+ Reply to Thread
Results 1 to 10 of 14

Hybrid View

  1. #1
    Join Date
    Jun 2009
    Posts
    7

    Default low voltage in bathroom exhaust fan

    I would like to repair an exhaust fan in a bathrooom.

    The fan does not turn on when the swich is flipped. The light switch on the same fixture (it is a leviton dual switch fixture) works fine.

    I began with the fan, as it is probably 20 years old. I opened the fixture from the bathroom side and found that the fan is mounted into a recessed fixure and then plugs in a 2 prong receptacle contained in the fixture.

    I removed the fan, motor, and plug and cleaned all the fluff from it. I then plugged it in a different wall outlet and it worked.

    I then reinstalled it, and it didn't work.

    I measured the voltage at the receptacle in the fan fixture at 40 volts. I took apart the fan fixture. I removed the wire nuts connecting the house line to the internal receptacle in the fan fixture. With the wall switch on, the house line measured only 40 on my volt meter. The identical fan in the other bath measured 120.

    I decided to replaced the switch. The wiring in the box has the hot wire enter via a GFCI and then act as a common to the 2 circuit switch. One then operates the light fixture in the BR (which works) and the other goes to the fan.

    I replaced the 2 circuit switch. The light worked and no fan.

    The receptacle in the exhaust fan fixture still showed low voltage.

    I then got in the attic and inspected the romex, which is intact for the few feet I can trace it before it dives down in the wall.

    What is my next step? It is a short in the house wire? Is the GFCI somehow limiting the fixture?

  2. #2
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,775

    Default Re: low voltage in bathroom exhaust fan

    Did you check both the hot and the neutral connections? It sounds like you have a high resistant connection. Do you by any chance have aluminum wiring?
    Jack
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  3. #3
    Join Date
    Jun 2009
    Posts
    7

    Default Re: low voltage in bathroom exhaust fan

    In terms of checking the hot and the neutral, would I check the black wire to the ground and then the white to ground? I only checked the black to white across the volt meter.

    The wiring is copper.

    Scott

  4. #4
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,775

    Default Re: low voltage in bathroom exhaust fan

    Check the black to ground, if you have 120 volts then the problem is the neutral. When you checked at the fan, did you remove the wire nuts and see if you had 120 volts on the bare ends of the white and black? It's possible that the receptacle in the fan case may be corroded.
    Jack
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  5. #5
    Join Date
    Feb 2009
    Posts
    693

    Default Re: low voltage in bathroom exhaust fan

    1. What are the voltage readings at the switch?

    2. Is the switch to the light in the fan on or off when you measure the 40 volts at the fan recept?

  6. #6
    Join Date
    Jun 2009
    Posts
    7

    Default Re: low voltage in bathroom exhaust fan

    I measured across the switch and the working light measures 120 v. The lower switch for the fan motor reads about 40.

    The measurements at the fan were with the switch off. That is, with the switch off, the measurement at the receptacle in the fan box is zero. With the switch on, it is 40ish. I can recall the exact number.

    Thanks,

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •