My master bath has 2 switches.
box The switch on the left (1) goes to the light. The one on the right (2) goes to the fan.

The light works fine. The fan only works intermittently. It takes 2-3 flips of the switch for the fan to come on. I've replaced the switch and the fan (it was old). I've sketched the circuit the best I can.


As you can see from the picture, A, B, and C are all in the switch box. There is one cable coming into the box and 2 going out. I've traced the cable to the fan through the attic and verified there are no other junctions.

I've got a multimeter and I've done voltage tests across every combination of the switches with ABC and everything on switch 2 seems to match switch 1 (when working and when not working).

Edit - tonight I swapped the black wires between the 2 switches (still using the quick connects for now). Same results. Fan still intermittently works but the light works fine. One thing I noticed during this process is that if I turn the fan switch from on to off and back on again very quickly, the fan works everytime. Is this at all significant?

Edit- I then disconnected and reconnected all the wiring within the box and connected the switch ground posts. I also used the screw posts instead of the quick connects. Same results. I was about to climb back into the attic to pull out the fan and return it when I decided to read the troubleshooting table in the manual. I've bolder the above from the previous edit for a reason. see answer below.

Is the only option at this point replacing the cable? Or am I missing something?

  • 2
    Actually, only the black wire is connected to the breaker, right? The white and bare wires are connected to the neutral (grounded) and grounding buses in the panel, respectively? Can you measure the voltage at the fan with the switch on? If you switch the wires to the fan and the light, does the light only come on intermittently? If you have a broken wire making minimal/intermittent contact, or a loose connection somewhere between the switch and the fan, then you have a heat and possibly sparking issue which could lead to a fire. Commented Jun 15, 2015 at 7:59
  • 5
    Two things I notice, though one of which would not cause your problem. First, the switches are not grounded. There should be a wire from the green grounding screw, to the grounding conductors in the box. Second, it looks like the switches are wired using the backstab connections. These terminals are known to cause poor connections on some devices (especially older devices), and are not the preferred connection method. Try using the screw terminals instead. It may not solve the problem, but it's worth a try.
    – Tester101
    Commented Jun 15, 2015 at 9:58
  • @Craig you're probably right about only the black being connected to the breaker itself although I haven't traced the wire back that way from the switch box since the other switch is working fine. My diagram should have said Panel instead. I'll switch the switches tonight and test that way.
    – kinar
    Commented Jun 15, 2015 at 13:24
  • 1
    @Tester101 Good call on the backstab connections! The loose connection could be in the switch itself. The only hitch is that the OP said the switch was replaced, so you would hope a new backstab connection on a new switch would be functional. Still, not a real fan of the backstab connections. Also, is that #12 (yellow jacket) wire? Most of those backstab connectors are rated for #14 and #12 could conceivably damage them, no? Commented Jun 15, 2015 at 15:17

2 Answers 2


This is symptomatic of a poor connection somewhere, or a bad-on-arrival fan. I'd rewire the switches using the screw terminals as a first step (don't forget to hook the grounds up when you do), and if that does not cure it, I'd try Craig's troubleshooting suggestion of switching the fan and the light. If the fan still acts up, then return the fan to wherever you bought it. If the light acts up when switched with the fan, then I'd say it's a problem with a connection.


Turns out im an idiot. This new fan is one with a Bluetooth speaker built in.

From the manual:

To operate the fan in speaker mode, turn the switch to the on position. To operate the fan in fan + bluetooth mode, turn the switch off and then back on again within 2s.

Doh! Thanks for the help everyone

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