Wiring diagram for spectrum HO 4-8-4 class J passenger version#612 item no.83903

[McTavish]

I have been asked by a friend to check out a Spectrum train & carriage.It belongs to a young boy who from what I'm told is in a wheelchair at the moment.It fell off the track setup sheared the wires connecting the loco to the carriage and broke a coupling.My friend took it to a model train repairer [in Australia] but after a few months was told it would take too long to fix [after charging $50.00 to check it out] So he asked if I would have a look as the boy misses his train.The reason for my email is to ask you if it's possible to email a wiring diagram as the 6 wires are all black and go to a small pcb CT003 so that I can reconnect the sheared wires and then test the train.
Submit: Submit To Service
Service said they had no wiring diagrams
Can anyone help ?