My suggestion would be disconnect the battery and start continuity testing the runs to see which goes where,
I’d check hand brake to fuse box as this is what should happen, then also the washer jet cable just to be sure. I do have heated jets but it runs directly to the fuse box iirc.
If the handbrake cable is the one behind the fuse box you think it is connect it to the correct output and see if it works (disconnect whatever is in there)
Then it’s a case of finding out what the cable in there does. So start tracing that using the same method.
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