J,
JohnJay & Rac66 are giving you sound advice. Today's elevator equipment is very complex. Elevator Professionals spend years working in the field and attending classes in order to complete there training.
Checking fuses and recycling the main line is one thing. But as you have stated you don't know what is "UPSTREAM". We wouldn't want you to do something that may put you in harms way. But more importantly we don't want your actions to put someone else in harms way.
We, as professionals who have years of practical experience, education and safety training are fully aware of the danger and hazards our industry.
It's obvious you have skills in related areas. I wouldn't recommend you apply your skills to this area. Taking this sort of chance to save what is not a lot of money doesn't justify risking others health or life.
