I made two versions of the 8404 tram.
In my first attempt I placed the battery box on top of the motor-bogie while the IR was in the adjacent section:
https://www.youtube....h?v=2J3W5NalZNY
Then I built a MOD 60097 tram. Due to the curved sides, there is not enough room for a battery box, so I used a regular 9V battery instead.
And then I rebuilt the 8404 tram converting it to the black/orange/bley colour scheme of the 60097 tram. i also used the 9V battery, which allowed moving the IR to the middle section.