@swoop

Thank you very much for your help, please let me know what your contact at Linde says, I appreciate it very much!

@MEngr

The switches on the axle just tell the wheels to swap directions when it gets to a certain position so that it spins on that axis. Ive taken your advice and checked them, it all seems to be ok.

@controlelectric
Whats your address? Ill get it posted today.
You can email it to infoATmikecostigan.co.uk

Hi Mike,
If you want to send it to me I would be happy to take a look at it for you, I normally charge a test fee but its only a small PCB so if I don't do any repairs there wouldn't be any charge just the return postage. If it is repaired you would be looking at £30 - £40 depending on the parts used.
Regards Shane

ok after carefully looking over the pic's mike sent this is my observations
- the box on the left side IS in fact a resistor pack (i think most of us agree on this now)
- the component (circuit board) on the right side i'm thinking is a steering interface board MAYBE combined into a drive contactor control
- the accelerator control even though it has the array of switches on it there was also an integrated circuit board he had to remove to show us the switches that also interacts with the contactors (could be interfaced with the steering control board.
- and also as MEngr pointed out, the 4 switches around the steering position indicator component in the middle of the truck panel area also may be an area of concern. check the wires from the switches and trace them, see where they go, if they go into that board on the right side then that confirms my suspicion that it may be a steering control board. If theres a problem with this board your contactors may not pull in correctly or at all and it very well could effect how the motor speeds for each side react.

As i pointed out before, check all the switches in the accelerator and make sure they are working properly, don't just listen for a click, use a VOM meter and check them. Do the same with the switches on the steering position module as well. If those steering switches stop working or get out of adjustment it will make the motors act up or not work properly.
Now as for that circuit board on the right side (what i'm calling the steering interface board) it looks to have several relays on it? there may be an issue with that but i'm not really sure how to check this without a wiring diagram of some kind. Like what was suggested, you may have to send it out and have it checked and/or repaired.

Of course this is all speculation on my part making educated guesses as to what these components are, without a manual i have no way to determine what they call these components. i do have a contact at linde and i will send him an email and see if he can provide me with any information that could be helpful, no guarantees on this but i will try.

TVH can supply conversion kits to update older forklifts from old fashioned multi contactor units to modern transistor control.

Might be worth looking in to.

TVH might also be able to diagnose / repair your current pcb unit.

@controlelectric

How much would you charge to have a look at the PCB?

Mike;
I was shocked to see you do have a resistor speed controlled vehicle. When three wheel trucks are in turning mode, the in board wheel will often be reduced in speed. I see steer switches on the steer axle. It is possible you may be having issues in this area.

My opinon after looking at all the pictures and watching the video is the time delay pcb is not working. Send it to controlelectric for repair :-). The 1st speed is working ok but the 2nd and 3rd speed contactors must be energized when the time delay lets them, and that isn't happening. If the foot switches for 2nd and 3rd speed seem ok then my guess is the time delay card.

Thank you guys for all your help!

Here's some photos:

The box on the left (look like a simple heatsink, but I guess thats what makes it a resistor box):
i.imgur.com/aTwkN4m.jpg

The PCB:
i.imgur.com/Gd3YM0g.jpg

And the pedal box:
i.imgur.com/OgyFc5H.jpg

AND A VIDEO!:
youtube.com/watch?v=8aiAngdlfyw

Old Chaps;
You may want to re-evaluate your thoughts. Linde has been using solid state drive control systems since 1961. The truck is produced in 1975 and according to descriptions of existing E12 323 of this time they are described as having SCR controls.

yes i had that same thought when i saw the box on the left side, it would either be a capacitor bank or resistor bank but without getting a better look at it i couldn't say for sure so i didn't mention it. If there is a cover on it and he can remove it he may just find it has resistor coils in it, if so i would check those real closely. But keep in mind he said he could manually engage the contactors and the truck would run faster. That is why i was leaning toward the accelerator control circuits.

As I said I have no info on this machine but when I have had the PCB in for repair the one shown on the RH side of the photo it looks like a timer card and although my first thought was the box on the LH side of the photo was a capacitor bank for a thyristor controller after a second look I am sure its a large resistor bank for a resistor controller. Mike does the box on the LH side contain what looks like large springs?

MEngr,
even though you have this info on the 323 series the E20 may be different than the E12. I'm sure there are a few similarities in both but a definitive diagnosis would only be speculation wouldn't it? The way mfg's love to make changes from one build to another would make me weary of the accuracy between the information obtained between the two units.

Mike;
The switch on far left is (C11) R.H. drive motor reverse, the next one to the right is R.H. drive motor forward, the third switch (RELAY) would be Hi speed R.H. drive motor forward, the forth Relay would be Hi speed R.H. drive motor reverse, and the following one would be the Line Contactor Relay. L.H. drive motor's direction control relays are to the right of the line contactor. The 19 inch box in the upper left houses the thyristors(SCRs) the main print board and other components of the traction drive's speed controller. After looking through my library the closet material I have to you truck is the E20 323.
A description of the truck's operation is as follows. This series of trucks were equipped with a safety brake switch so that when the parking or foot brake were applied all power was turned off making the truck inoperative.
Power is supplied by a 24 volt battery for all functions. When the battery was plugged in, the ignition switch turned on, and the parking brake turned off, voltage was applied to a zener diode and resistor which applied 8 volts to the card section. Upon depressing the drive pedal the directional switch would actuate and tell the truck which direction to travel. The 10 degree switch turned on the SCR to produce power in the SCR range. The 90 degree switch sent the truck into Hi speed dropping out the SCR speed range. If the motor reach 90% of its speed the Hi speed contactors or bridge contactors would close. When the truck was under a load and the drive pedal depressed were the 90 degree switch was actuated the bridge contactors would close.

I am sure the controller is an old resistor type, I have never seen one in a truck before but I have had the cards in for repair (the PCB with the 2 relays on the right hand side of the photo) which is a timer card used to give a delay between speeds (gears). The fault is most likely to be either a wiring fault between the foot pedal and the timer card or a faulty timer card. unfortunately I don't have any wiring diagrams to help you check out the wiring.
Regards Shane

I hef to install old version truck expart new version no info for dis truck

hey mike,
well i checked linde's website and that model or serial does not come up as a good number for me
it could be that i do not have access to the european trucks if they have another part of the site for those.
From the number you gave though this truck is a 1975 model truck, it is possible they do not have information that far back.
Maybe someone else can help that may have information on this unit.

But from your description of the problem i would check the switches in the accelerator pedal box and make sure they are all working, use a vom meter and check them.
Also check back at the contactors (the big electromagnet contacts as you put it) and see if they are even getting a signal to energise when the accel pedal is pressed. (you'll want to have the drive wheels jacked up off the floor for these tests) Each one will have 2 wires connected to each coil, check for voltage there and make sure they are getting a negative signal as well. Most systems today use negative switching but one that old may not.


good luck

Hi guys, thanks for the support!
Serial number: 3234704144/1975

Mike;
From the description you have a three wheel sit down c'balance Bosch SCR Linde produced in the 1980's. A serial number would be of help in helping you.