Hi Elektrodrive,
Your porblem is really strange and I never met this before. The following is just idea for you & do hope it may help you to find the thing :
- If the truck with LID (display) removed or LID defecitve it can work normally but the traction speed will be reduced at low speed.
- Check the output of DC - DC converter 48/24VDC if the output is enough 24 VDC when LID installed ?
- In order to check if one of the outputs of LID is shortcircuit you should try to unplug all connectors for cooling fans, heigth sensors, brake fluid sensor,...) and see if the LID will display ?

- Or you can try to connect only the power supply and canbus connection for LID to see if if the LID will display ? By this way: from the connector 6X1 for LID (16 pins), use some wiring to connect
=> Pin 1 (6X1:1) of connector female 6X1 to respective the male connector pin of LID to supply + 24 VDC (black red color)
=> Pin 1 (6X1:16) of connector female 6X1 to respective the male connector pin of LID to supply 0 VDC (blue).
=> Pin 1 (6X1:14) of connector female 6X1 to respective the male connector pin of LID to supply the CAN high signal (Violet white).
=> Pin 1 (6X1:15) of connector female 6X1 to respective the male connector pin of LID to supply the CAN Low signal (Violet Red).
=> Pin 1 (6X1:3) of connector female 6X1 to respective the male connector pin of LID to supply + 48VDC of battery (Orange).
- If not, you must check the CANbus signal to the LID by measuring the resitant between CAN High & CAN Low (6X1:15 & 14) in order to know if it = 60 Ohm ? if not the canbus signal is missing and you need to check the wiring otherwise you couldn't get the LID display. This is because, the power supply only help the LID to light up but all information must be received from the canbus system.



Let me know your checking result.
Good luck
Regards
Nuna