Can’t install Yoke/harness

I have a tamed horse, a 8” yoke and a specially made chariot/cart. But I can’t install the yoke into the vehicle, it just does not appear as an option, do I need a certain level of mechanics or something? (I’m at 7th level right now)

i believe that level is more than enough, are you positioning it correctly?, it has to be on on the front side i believe (up on the vehicle UI) and it only can be installed on the adjacent frame, not in the frame that will carry it

iirc, a harness is an external part.
i.e it needs to be installed onto empty space, with no frame underneath it.