Nordictrack C1800S Treadmill - Suddenly Stopped - Speed Settings go to Zero - Motor not spinning

edited January 2021 in Treadmill Problems
The treadmill stopped suddenly. The treadmill used to make some noise after using for 30 to 40 minutes and go away. It suddenly stopped one day. Will that be a motor problem? I replaced the drive belt recently, which was almost worn out. The treadmill is about 15 years old and heavily used. The speed setting on the display goes to zero immediately after setting it for any speed. Is that a control board issue? Or, because of the motor is not running? I bought a new motor and try to connect the wires to the board to see whether motor is spinning and it's not. The new motor is not connected permanently to the treadmill. I have to remove the pully from the old motor. I wanted to whether it's control board issue or not first.

Could someone help me to troubleshoot? Thanks in advance.


  • I have an update. I tested the motor with cordless drill 18V battery and the motor was spinning. It's now confirmed that I don't have problem with the motor. I tested the DC voltage coming from the control board and it's only 2V. Is it maybe due to the speed control doesn't work? The speed settings go to zero within seconds. It doesn't stay at the speed I wanted to have. The motor is not spinning maybe due to speed control is not working. Could someone advise me what could be the problem? I don't want to go ahead and spend money on control board without knowing that is the problem. Thanks in advance.
  • Sounds really like a motor controller issue.
  • Thanks for your response admin-it. Before I go ahead and change the motor controller, I wanted to discuss one thing with you. Please note LD4 doesn't lid on the board. This is the only one doesn't lid. Is this the one for commanding motor to run and keep the speed settings to stay on? Please advise. If the motor controller is bad, how much is for the board? Thanks in advance.
  • Is it possible to upload pictures to make it easy to explain? Please advise. Thanks.
  • You are supposed to have 6-12v - if you only have 2v on the wires from the control board then the control board is bad and needs replacing...

    what is your model number?
  • Thanks for your timely response. I truly appreciate it. The Model Number is Nordictrack C1800S.
  • we need the complete model number to verify correct item information
  • The Model Number is NTTL9912 Nordic Track C1800S. Thanks for your assistance.
  • ok - looks like you are going to have to call in and special order this control board - I apologize for not having a direct link to this product!

    888-362-1105 then push 2
  • Thanks a lot. I just called and ordered a motor control board. Thanks again.
  • yay glad we could help! have a great rest of your week and let us know if you need anything else!
  • I got the upgraded motor control panel and the Treadmill came back to life. Few things are being observed now. It starts faster in the beginning and scares everyone. When I press speed setting at 1mph it takes it to 2.5 mph and slows down after that. But, it scares people. And, the speed settings are always fluctuating. Say, when the speed setting is at 3 mph it goes back and forth between 3 to 3.4 or 3.5 mph. I did the calibration as described in the repair forum for upgraded motor control panel. Is it something we can do about it? Please advise. Thanks.
  • sounds like there could be a short in the wiring - or they could be crimped somewhere
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