Can I fix harness

Sure ... if you can match the colors on the mating half here's what .. first if you can find the fuse that's for the rear wiper ,, pull it out then you plug the wireless connector into it's mate ... next slide the wire ends into the opening that matches the other sides color .. if you screw up and need to change holes then ,,, unplug the connector with the wires you already put in ,,,, turn that connector so the mating side is facing you ,,, then get a large safety pin and while pushing the wire forward stick the pin in to unlock the wire ... take a look at the connectors on the loose wires and you will see a little tab that locks it in place so you know exactly where to put the pin into the connector to release the wire

If a wire fails to stay in than either the locking tab a bent or broken ,,, if that happens after all the wires are back into the plug securely ...get a tyrap and pull it very tight on the harness ... the other wires will hold the bad connector in place