Electrical problems 2002 g500

I write from Canada, the following things do not work on my 2002 Mercedes G 500:Sitz verstellung electric driver side,window lift left,seat heating left,Left exterior mirror can’t be adjusted,central clearance left opens and does not close, everything on the left side? Have new left wire harness installed on suspicion !Everything at the old ,what should I do to get out what is wrong? Please help,schoenenen Thank you.