Discussion:
Drive Motor doesn't run

The hydraulics come on, so raise/lower/tilt work fine but when I throttle forward or reverse, I can hear (and see) the contactors pull in, but the drive motor does little more than an occasional twitch???

Any thoughts? This is an older machine, so no circuit boards, it seems to just have two contactors for fwd and reverse and a big honkin old SCR... and of course the motor. Not a lot to go wrong, I'd think!

Also, anyone know where I could find a manual for this machine? It would be nice to know if I'm putting the right oil in there
  • Posted 5 Aug 2014 15:33
  • By rob_c
  • joined 5 Aug'14 - 9 messages
  • Pennsylvania, United States
Showing items 21 - 22 of 22 results.
this truck have the cableform contactors on it?

try this trick and see if it just needs a new contactor kit
jack the drive wheel(s) off the floor
activate the drive in either direction and then wiggle the direction contactor that is pulled in and see if it takes off running. These contactors were well known for failing even though they did look ok and appeared to pull in. The armature of the contactor can get worn and hang/bind up.

I would also check the accelerator pot with a vom and make sure it has full range.
And of course double check the motor brushes, grab the leads and pull them out a bit and let them pop back in place, this will tell you if they are worn out too much or are hanging up in the brush holders. And like kevin says, look at the condition of the armature and make sure its not arc'd up and damaged. A good armature surface will have a smooth surface and be a chocolate brown color or shiny copper where the brushes ride.
  • Posted 5 Aug 2014 20:22
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
What condition do the motor Brush's look like worn out are they? How about the commutator that they ride on???
What is the serial number of the truck?
  • Posted 5 Aug 2014 15:56
  • By kevin_t
  • joined 2 Dec'10 - 1,301 messages
  • Pennsylvania, United States

Post your Reply

Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.

If you are having trouble using the Discussion Forums, please contact us for help.

SMV (Konecranes) 4632TC5
Balling, Denmark
Used - Sale
Kalmar-Ac P100CXD
Morgantown, Pennsylvania, United States
Used - Sale
Latest job alerts …
Tampa/Orlando Florida, United States
Dallas, TX or Lexington, KY, United States
Fact of the week
The word "okay" (or its abbreviation "OK") originated as a humorous misspelling. In the 1830s, a fad in Boston involved using abbreviations of intentionally misspelled phrases. "OK" stood for "oll korrect," a playful mispronunciation of "all correct".
SMV (Konecranes) 4632TC5
Balling, Denmark
Used - Sale
Kalmar-Ac P100CXD
Morgantown, Pennsylvania, United States
Used - Sale
Upcoming industry events …
October 29-31, 2025 - Marina Bay Sands, Singapore
March 10-12, 2026 - Hong Kong, Hong Kong
Movers & Shakers
Steve Dimitrovski Steve Dimitrovski
Director sales for Australia and New Zealand, Swisslog
General Manager, Forkpro Australia
Global CEO, Swisslog
Board member, UKMHA