Plarail Advance series 165 reverse function issues

Hello, 
this is my first message on this forum.
I am having issues with the reverse function with the Plarail Advance Series 165. When I take the cover off, the reverse function works fine, but as soon as I put the cover back on, I can only make the train go forward. Does anyone have a solution for this?

[Super]

Hello Loreful, welcome to BPT's. Hopefully a member who has knowledge with the Advance trains can help as soon as possible.

maybe the motor is loose?  i would look at the chassis to see if there are any loose parts.

Is it simply that the switch is fouling on the train body and not allowing the switch to make contact when you try reverse?  If so it may be you need to file the slot to make it a bit wider and allow the switch to move further...

I've not come across this problem before, but if it works fine without the body on its the only thing that springs to mind.  Could you take some pictures of the switch unit with the cover on in all positions?  You know forwards/off/reverse...

[Super]

Thanks Nigel

Thanks Nigel

You're welcome, its the only thing that springs to mind if it works fine without the cover on

The other thing that could be tested would be to put the 165 body shell onto another motor unit or another body shell onto the 165 motor and see if the problem moves if that makes sense as the motor units are all identical its just the shells that change