Each light in an E46 receives its own individual power from the LCU which are all switched by transistors, so I would be concerned about overloading that branches transistor and causing more damage. Did it blow a fuse? If the failed circuit is truly shorted out you'd think it would, and take the other headlight with it. Plus in the end you'll have the headlight-out lights on all the time due to the unbalanced load.
You'd be better off getting that wire and/or circuit fixed properly. It is the smarter and safer way to do it. And good tech should be able to figure that out.