Discussion:
Forward/ reverse problems.

Suddenly I can not get my forklift to go into FOR/ REV Let me back up. If I turn of key (reset PMT) turn back on put in FOR I can get it to go. After a couple of rounds of FOR/ stop /FOR it will no longer go FOR. If I turn off key most times it will go FOR again only to go through the same deal. Once in a rare while it will go into REV. Usually on one time. ie if I go into FOR and then back to REV nothing. Sometimes if reset it tries to go into REV ie. contact moves a little. If I push manually at that point it will engage. usually only one cycle though then contact will not move at all and even pushing contact will not engage.
I have 37.6 V across Battery even though it is 10 years or so old. 2rec and 5 rec were replaced a while ago (3 months) due to an unrelated problem ie the surge/ stall scenario. Main card was replaced a month before that to solve an intermittent problem where it would just stop dead in its tracks problem.
I have 37 V at contacts when switch is on. I have 37 V at FOR/REV switch terminals except one that is 10V.. I've cleaned contacts on FOR/REV contactors. Throttle potentiometer seems to work properly (speed increase smoothly till 1A kicks in). All hydraulics work properly. seat switch / brake switches all work as intended. Handbrake switch is bypassed. Si thats most of what I know. Forklift repair guys now just says its the battery. Don't know as I have 37 V (assume all cells are good then??)
Love any input. Key I think is the sudden natuire of the problem. Last week drove all day no problem. Next day nothing
  • Posted 21 Sep 2011 10:02
  • By sbaussie
  • joined 21 Sep'11 - 6 messages
  • California, United States
Showing items 1 - 5 of 5 results.
Halleluyah. Remove FOR/REV contacts completely from forklift. Completely dismantled. Little deposit on plunger. Wire brushed it off. cleaned everything with brake cleaner. sprayed it with graphite, reassembled and voila It works perfectly so far. About an hours worth of wharehouse work. Will put it through a few heavy days this week and see. Let me see if I have this right. I put into forward it tries to close contact maybe draws a little more than it should and trips PMT.
does that make sense. Just by the way what is the little unit on the side of the FOR/ REV contact looks like two diodes and a thermocouple?? its in line with the small wire connections?
thanks to all
  • Posted 22 Sep 2011 11:00
  • By sbaussie
  • joined 21 Sep'11 - 6 messages
  • California, United States
Thanks for the response.
-Panel/ Control card is EV -100TLT1A
Model ERC050JAN36 serial 483655
Will have a rental 36V here this afternoon so I will be able to eliminate or confirm battery as source of problem.
Will pull contacts out and check.
  • Posted 22 Sep 2011 06:07
  • By sbaussie
  • joined 21 Sep'11 - 6 messages
  • California, United States
Could be different condition of moving parts in contactor. Reverse may have more resistance to movement due to wear, dirt, etc. Also helpful to know truck information or at least the panel.

Sorry just noted the info in the header.
  • Posted 22 Sep 2011 01:21
  • Modified 22 Sep 2011 01:22 by poster
  • By JFStewart
  • joined 20 Sep'11 - 6 messages
  • Ontario, Canada
Will check Voltage as you recommend. Plenty across battery 37.6 but I agree under load could be an issue. Any real reason why if dislikes going into reverse more than forward, also the very sudden nature of the problem??
  • Posted 22 Sep 2011 00:50
  • By sbaussie
  • joined 21 Sep'11 - 6 messages
  • California, United States
Most batteries don't last 10 years. You have done well my son.

What make, model, and panel do you have? Are there any fault codes displayed?

What is the voltage under load? Operate tilt back into relief, read voltage at that point.

Problem sounds like battery as you have to press the contactor in. That indicates that there is not enough voltage to draw the contactor in, but once in there is enough "hold in voltage" to keep it engaged.
  • Posted 21 Sep 2011 23:22
  • Modified 21 Sep 2011 23:24 by poster
  • By JFStewart
  • joined 20 Sep'11 - 6 messages
  • Ontario, Canada

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