Crown RC3000:
No forward or reverse after short repaired in wiring

Ser #1A222551


This forklift was operating great for a long time before this issue arose. machine has been used and abused in a heavy equip. repair shop. rear wheels are kidney killers and machine was bouncing around all over the place before failure...

It started blowing fuse F6 immediately upon plugging in battery. I found and repaired a short in the wiring, it was a twisted set of wires going to a 5 terminal block next to the hydraulic filter inside left rear pillar of machine. wires from the block then go to a small alarm right beside it. The FU6 is no longer blowing.

But now lift has no FWD or REV. When moving handle forward or rear there is no clicking, sounds, nothing changes. ALL other controls on machine work. The switch under the front plate where you stand is jumped. At the card (EV100?), I checked the inputs coming from the two steer limit switches and they seem to be correct. There is a 3rd switch with the other two steer limit switches i do not remember which one it is but the input for it is also correct. I checked the 6 pins at the card, all voltages seem to be correct here. Accel input, changes from 5v to 0v when moved. voltages are correct for brake switch, key switch, fwd and rev switches. I have 18v going to the forward and reverse contactors on the middle posts, and 36v at all the control wires going to both contactors. I have 36v at the 4 terminals for the forward and reverse switches right under the handle. We have another RC3000 in the shop with its own problems, and another that we use for parts. I'm not sure what half of this stuff is without a manual or experience with these things. But I've tried a different handle from the parts forklift, swapped as an assembly, wiring, and 3 wire potentiometer? I've tried several different cards, (EV100?).. I've tried several different boards (the one that has 9 terminals on one side and 11 on the other.. I've tried a different SCR controller, the little diodes that surround it, tried a different capacitor... and a few other things im forgetting and I'm getting nowhere. What are some more tests I can do and what are the proper way to check them? I have surfed around a little on just the general Crown repair forums, do you really need to remove the larger amp fuses to properly check them? I have continuity across all fuses, small and large, what is correct way to test potentiometer? or micro switches for handle?
  • Posted 18 Jun 2019 05:35
  • Modified 22 Jun 2019 14:11 by poster
  • Discussion started by jackson_p
  • Tennessee, United States
Showing items 31 - 31 of 31 results.
Any help would be greatly appreciated.
  • Posted 22 Jun 2019 13:44
  • Reply by jackson_p
  • Tennessee, United States

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