^ Garage, dealer, service center it does not matter. None of them do electrical repairs,they just take out the unit and plug another one in.
I had an alternator fault,the garage said it was faulty and needed a replacement at £380. I called out an auto electrician who looked at it and replaced the brushes and contacts It cost £15 ,took 30 minutes and worked perfectly,it continued working perfectly until I sold the car several years later. £365 saved over the garage price