Well,
it was the sideshift joystick.

Since I don't have any diagnostic tool I used description of faults.
I have checked all inputs were a fault turns off the hydraulics.

The sideshift joystick was a little off with his voltage when in neutral upon key on. I have turned the potentiometer on his shaft until he was showing 7.1 V in neutral. After the next key on the hydraulics turned on.

Now, all hydraulics work except the sideshift which turns off when I push the joystick fully to the right. I've checked the voltage and it doesn't go out of range.

What do you think?

Yes,
I tought a control module problem too, but I wanna be sure of course.

Also, it seems that the control module has already been fixed cause it has some unusual stickers on.

Well - it looks like a control module problem.
Check your mail,
I send you catalogue page where you can identify the modules (you may have the version with two independent modules or one integrated, (pos. 28, 29 or 29a)
I send you also the description of the pins and signals on the independent lift module.
Use it for checking.
Good luck

Hello,
I've just got back from the machine.

Here are the facts:

- lift/tilt/sideshift hydraulics do not work

- hyd. pump doesn't activate when moving the joysticks
- there's no power supply to "hydraulic enable" solenoid valve
- "hydraulic enable" solenoid valve coil OK
- joysticks input and output OK
- switching joysticks doesn't help

- steering OK (it activates the hydraulic pump)
- drive OK
- double module A1 OK (left motor and hyd. pump)
- power supply to main control unit A2 OK

- no warnings on the dashboard instrument
- hourmeter and battery discharge level meter OK

- battery voltage and all fusses OK
- voltage converter OK
- seat switch OK
- handbrake and service brake switch OK
- emergency isolator OK

What inputs must be present to make the hydraulics work?

OK, thanks.

As I've written - may be several issues - from the pump to the control module.

Is there no hydraulics at all?
Is there some additional hydraulics installed on the truck (sideshift)?
If yes - is it deactivated too?
If it works - this is probably a joystick issue.
So put the joystick from the extra hydraulics to the socket of main hydraulics. This will confirm the failure.

Is the motor pump working?
If no - probably you have issues with the hydraulics control module.
If yes - check the pump nad pressures before and after the control valve.

Of course - on the beginning, check the battery condition.
The truck may have the hydraulics "switch off" function, when the battery is too weak or discharged.

Unfortunately Linde developed this truck only to be diagnosed with diagnostic software.

Any ideas beside joystick?

It's 335.
I don't have any soft.

May be a lot of issues.
What series is this 335 or 336?
Or perhaps 386?

Probably joystick problem.
Truck Doctor or Pathfinder (Linde softs) would be usefull.