Crown 20MT:
No Power

Hi all new to forum and this is my first post so any help much appreciated.
I have recently acquired a used Crown 20MT90A to replace a 15MS64A that didn't quiet have the lift height i needed.
As i plan to use it in a home garage work storage enviroment.

The 20 had been sitting out in the weather for past 18 months so it has it's share of surface rust dirt and bird poo lol

Below is a list of what i have done to fault find.
Surprisingly internal wiring and connection are fairly clean no signs of any major corrosion.
Check oil
Replace battery's with ones from my 15
Bypass key as i don't have one with it
Check door switch and manual lift leaver switch
Connected external 12v to pump motor terminal and that works fine

The problem
I am getting a reading of 6v on multi meter from - batt terminal to key terminal that I bridged, but no power to any functions not even the horn I cant hear any clicking of solenoids only the micro switches when handle controls are moved or pressed although up raise does not click.
Bridging large wires either side pump solinoid works pump.
When looking over things the far left contactor i think it's called has a crack in the mount not sure if its contributing to any of the issues

I would like to test the drive motor but am unsure of what wire is what could someone advise what the 4 wires are please and where to connect 12v jumpers to if possible.

Also any help in where i should start looking to track faults would be much appreciated.

I'm happy to swap parts from 15 if needed to eliminate faults just not sure where to start.
Sorry for a long winded first post.

Thanks again
  • Posted 16 Sep 2016 07:31
  • Modified 16 Sep 2016 08:17 by poster
  • Discussion started by rbr77
  • New South Wales, Australia
Showing items 1 - 3 of 3 results.
Ok checked through suggestions with no luck
all fuses are good
I have 12.34v at key
No lift or motor movement when pushing in contactors / buttons / lift lever' whilst handle and door switches engaged.
Battery's are definitely good as they come from my other working fork.
When checking voltage at bridged key terminal i did notice two other wires White with red stripe that were disconnected and taped one had 2910 and the other 2920 printed on them i tried connecting them also no change, Could you advise what they might do also ?

Again all help appreciated
  • Posted 17 Sep 2016 02:20
  • Reply by rbr77
  • New South Wales, Australia
Thanks for the prompt reply will check above points tomorrow.
and let you know.
BTW it has no gauge
also is it possible to connect a 12v batt via jumper leads direct to motor bypassing contactors

Thanks again
  • Posted 16 Sep 2016 21:32
  • Modified 16 Sep 2016 21:37 by poster
  • Reply by rbr77
  • New South Wales, Australia
To test the drive motor, open door, jack & block chassis so drive wheel is free of the ground, pull handle down to release brake and push either of the contactors on the right hand side of the door, one is forward and the other reverse. The drive wheel should turn slowly. Middle contactor is second speed, both the left hand contactors have to operate for top speed as it changes the batteries from a parallel 12v configuration to a series 24v configuration.

When testing voltage, the terminal on the pump motor facing you when you open the door is common negative, use that. Both the cables going to the quick disconnect plug are positives, one for the chassis battery pair and one for the door battery pair, check from the neg to each of those first to make sure you have 12v on each. Check aforementioned neg to keyswitch again. If you bridge keyswitch and door switch you should have lift. Check single glass fuse under main terminal block between batteries. Also fuses to either side of contactors. Does it have a battery gauge? My email is in my profile.
  • Posted 16 Sep 2016 17:41
  • Reply by techno_nz
  • Canterbury, New Zealand

Having trouble using the Discussion Forums? Contact us for help. accepts no responsibility for forum content and requires forum participants to adhere to the rules. Click here for more information.

Movers & Shakers
Mark MacDonald Mark MacDonald
President, Palletiser Division, Columbia Machine
President, Action Lift
Chair , Lifting Equipment Engineers Association
President and Chief Executive Officer , Kalmar
Global Industry News
edition #1155 - 23 November 2023
More and more warehouses around the world are turning to robots, as we see in this week’s news with a German fulfilment centre adding robotic assistance... Continue reading
Mitsubishi RB16N
Queensland, Australia
Used - Sale
Toyota 8FD45
Yokohama, Japan
Used - Sale
Upcoming industry events …
March 11-14, 2024 - Atlanta, United States
May 14-15, 2024 - Warwickshire, United Kingdom
May 15-17, 2024 - Singapore, Singapore
Elwell-Parker ESI500-36
Coraopolis, Pennsylvania, United States
Used - Sale & Hire
UN Forklift FB25N1LZ1
HANGZHOU, Zhejiang, China
New - Sale

Showcased in the Virtual Expo

Exide Technologies heavy-duty Tensor battery
Latest job alerts …
Minneapolis, United States
Kortrijk, Belgium
Louisville, KY, United States
Edison New Jersey, United States
Fact of the week
The concept of Daylight Saving Time (DST) was first implemented in Port Arthur, Ontario, Canada in 1908. The first proposal for DST, however, came in 1895 from New Zealand entomologist George Hudson who valued extra daylight so that he could hunt bugs after work during the summer months. He suggested a two-hour daylight-saving shift.