How Do I Test The AC Motor Cable? - TigerStop

Call Us

TigerStop Customer Service

Phone: +1 (360) 448 6102

TigerStop Sales

Phone: +1 (360) 254 0661 ext 2

TigerStop Headquarters

Phone: +1 (360) 254-0661




  • Unplug the 19-pin connector from the motor
  • Turn off, unplug power & open amplifier enclosure

Items Required:

  • Multimeter &  Motor Cable Pinout (previous FAQ)


  • Ohm out the motor itself, at the 19-pin connector. You should expect 2-4 ohms between the phases (B-C, C-D, B-D) and open circuit from each phase to ground (B-R, C-R, D-R)
  • Examine the connector, on both sides. The pins should be a uniform length with no scorching or oxidation. The cups on the female side should be a uniform height as well, and similarly clean
  • The pin-out shows which pins on the female 19-pin connector should be connected to which wires inside the amplifier. Unplug before opening the amplifier. Make sure that these connections are good, and also that there aren’t shorts between connection points (e.g. pin R should be connected to the motor ground and ONLY to the motor ground)
  • Reconnect the 19-pin connector and re-ohm the motor from the wires inside the amplifier. You are expecting the same resistances as before, plus a small amount for the intervening cable. Each phase must be open line to the ground wire
  • Please report these results