Older NordicTrack EXP1000i (NTTL09900) - hot motor and speed control issue

1. Treadmill is old but low mileage. Burning smell - opened cover and motor was hot to touch.
2. Researched online - found TMD. Walking belt and deck have never been lubricated. I did not have the means to measure amperage at this point. Ordered silicone. Cleaned and lubricated belt/deck.
3. I also purchased a DC shunt resistor (50A=50mV) to try to measure motor amps. Unfortunately, my old analog multimeter lowest scale is 0-125mV so I could not discern measurements in the 0-10mV range. But it did seem to be high. I will borrow a better meter.
4. In testing the treadmill in the interim, I have noticed that at no load the speed stays consistent. When walking on it, the speed increases by .5 to 1 mph. Strange. I didn't find any discussions that addressed that specifically. We can probably live with this.
5. Also I was able to easily stall the motor by stepping on and holding the walk belt. Hoping all my issues were the motor brushes. I inspected and the brushes looked okay. The commutator was a little dirty so I cleaned it up. The torque is definitely better.
6. Now I have a better meter. At 2.5 mph: no load = 4A, load = 10A, full incline w/load = 6.5-7A
So. The brushes/commutator probably weren't my only problem. Do you think a new belt is indicated? It doesn't make sense that a worn belt would cause speed up under load.


  • Try lubricating the belt again. if that doesn't help, replacing the belt is what I recommend . The amps are a little high. should be about 6-8 with a load.
  • The controller may be ready to fail I would replace the belt first and go from there.
  • edited January 26
    Hi Kevin. Thank you for your responses.

    I did add more silicone and ran the treadmill. The current draw seems about the same. I walked for a little while thinking maybe the silicone would work in and operation might normalize. I did have a brief moment when the speed was correct and the amperage was in the 6-8 range. But mostly it ran 1-1.5 mph over input speed of 2.5 and amperage was over 10.

    Then....The speed dropped to 0.9 mph. When I unloaded the belt, speed returned to normal. Reloading the belt resumed typical operation of overspeed and overdraw. This drop to 0.9 continued to happen after a few minutes of walking.

    So....It appears that you may be correct about the speed controller. Does it make sense that it can maintain consistent speed unloaded but not loaded? Incidentally, the QC label on the large white brick-shaped component on the board appears to have gotten a little "toasty". (Or maybe it's just the adhesive that browned with age?)

    Therefore, I should purchase a control board and a belt? (Presuming this machine is worth the investment?)

  • yes, Use this code on the checkout page for a 5% discount (5offkevin)
  • Hi Kevin-
    Thanks for your help.

    I installed the new walking belt and speed controller. The treadmill speed control appears to operate correctly.

    However the current draw seems high: at 2.5 mph, unloaded = 5 A, loaded = 11 A.
    My initial measurements after belt installation were more in the desired range, but increased to the above numbers as I tensioned the belt until it stopped slipping. (This also drew the belt up against the bottom of the deck sufficiently to keep it from riding on the ends of the belt guides.) Do you have any further recommendations?

    The disassembly for the walking belt installation was a challenge with the one piece rear end cap and the retaining clips holding the rear roller shaft to it. The front roller had to come out first. The exploded parts diagram in my manual helped me to figure it all out.

    Thank you.
  • Lubricate the walking belt real good and check the amp Draw again.
  • Hi Kevin-
    Additional lubricating did not seem to make a difference in the amperage draw.

    I un-tensioned the drive belt a turn to see if I hadn't over tightened it trying to get rid of slippage. No difference in amps but more slippage.

    I loosened the drive belt tension bolt to see if I hadn't over-tensioned the belt. With just the weight of the motor to tension the belt, a cyclic "jumping" of the motor was noticeable. Upon inspection, I could see that the grooving on the belt was deformed. So I will need to order a new one. Not sure if that could cause that much additional load on the motor?
  • What does the surface of the deck look like/feel like? is it slippery and smooth or are there grooves in it?
  • Deck surface is smooth - no defects.
  • unloaded = 5 A, loaded = 11 A. This is a little high. does the motor get hot after use? typically, you can hold your hand on the motor after its used. it'll be warm but not hot.
Sign In or Register to comment.