Brake question

I just purchased a 24 foot Komfort kampsite trailer and while getting new tires put on, I noticed that the driver side axles have wires running to the brakes but the passenger side wires have been cut and capped. Is this normal or do I need to get those wires on the passenger side hook back up? When I use the trailer brake in the truck while driving it home, the brakes did work on the trailer but I am guessing they are only coming from one side?
Thank you in advance for any help. I appreciate it.

David