I have a non-working oscillation 3-speed fan. After some detective work, I found that both wires going into the start capacitor are hot. Is this what it should be?

There are three wires, maybe four (3 speed plus neutral), going into the motor coil and two wires coming out of it. These two wires go to each end of a capacitor. The capacitor is rated at 1.5 uF. I tested it and it was 1.2 uF. So, I bought a new one to replace it. After the replacement, the fan still wouldn't work. I checked the two wires and found that both were hot. I don't think this is what it should be, correct?

  • Hot as in "there is a voltage on them" or hot as in "they are literally hot to the touch"?
    – Mołot
    Oct 4, 2019 at 14:28
  • There was voltage as tester was lighted.
    – joehua
    Oct 4, 2019 at 16:04
  • Did the fan ever work? What's its history (i.e. some clever idiot modified it and then gave it to you)? What's the other end of those two wires to the cap? Oct 4, 2019 at 18:02
  • 1
    Voltage: are you measuring DC or AC voltage, and with respect to what reference? Oct 4, 2019 at 18:03
  • Yes. The fan did work. When I first bought and installed it (a wall fan), it worked. Then, no one stayed in that room for two years. I checked the fan the other day and found it not working.
    – joehua
    Oct 5, 2019 at 0:09

1 Answer 1


Don’t start changing the wires! Those pens are not a good way to troubleshoot. Don’t start shotgunning parts without some basic troubleshooting. For example I have a 3 speed fan that worked great all summer. One cool day we turned it off, another day it would not turn on at any of the speeds. I unplugged it opened it and spun the blades , they were stiff, it did not turn a full 360. I dribbled some light oil in the bearing close to the blades while turning by hand it freed up. I continued very slowly adding oil and spinning , wiped the excess oil and put it back together. The fan still works every day my grandson turns it on after school to see if it still works.

In my experience small fan motors fail because of dry bearings almost never the switch or capacitor. I have brought dozens if not hundreds of fans to life using light oil (will get slammed but wd40 works to get thing moving) 3 in 1 is better but a simple 30 weight oil will also work and last longer but takes a little get to get things free.

  • I actually replaced capacitor in five ceiling fans so they would run again but they are about 20 years old. The fan in this post is only two years old. The blade is free spinning if moved by hand. For the capacitor, I expect only one hot wire into the capacitor. The purpose of this post is to see if someone would come out and confirm that yeah, there should only be one hot wire going to the capacitor. Then, I'd just throw the fan away because I can't fix anything inside the coil.
    – joehua
    Oct 5, 2019 at 21:49
  • You should get a real meter, non contact meters are in no way a true diagnostic tool other for the possible voltage present on a wire I am glad shotgunning parts has helped you but as a professional I measure the caps or at a minimum check for a charge and discharge using an ohm meter if the meter doesn’t hav a cap tester. A cap sets up a phase shift to help the motor ether start / run. Voltage on 1 side of the fan coil will provide a voltage on a different winding that is not even connected , we call that phantom voltage and this is why non contact testers are not a diagnostic tool.
    – Ed Beal
    Oct 6, 2019 at 18:58
  • I did use a multimeter to measure the voltage across the two wires going to the capacitor and it read 0. I thought there was no voltage until I tested them with a tester pen and it lighted up. That's when I realized that both wires were charged. I did use the multimeter to measure the capacitor. Although it was rated at 1.5 uF, the reading showed 1.1 uF. I purchased a new 1.5 uF capacitor and the multimeter showed it as 1.6 uF.
    – joehua
    Oct 7, 2019 at 1:41
  • Per your comment “the voltage tester lighted”. Maybe you need to learn how to take measurements . Capacitors within 10% of their rated value are good.
    – Ed Beal
    Oct 7, 2019 at 13:25
  • The capacitor was rated at 1.5 uF. As I stated earlier, it was 1.1 uF when I tested it with the multimeter. So, I purchased a new one which the meter showed to be 1.58 uF. I replaced the old capacitor with the new one. The fan still didn't turn
    – joehua
    Oct 8, 2019 at 4:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.