To anchor a block in a drawing:
- Select an endpoint of a line in the block.
- Add a fixed relation to this point.
The con of doing this is finding the fixed relation sometime in the future if you wish to move the block. You probably also could fix an arbitrary sketch point somewhere in the drawing (with a fixed relation), and dimension all of your blocks to this point, then hide the dimensions. Then you can unhide the dimensions in the future to move the blocks, maybe more user friendly then fixing a point on your blocks.
Still might be another way to do this, as I don't often do wiring diagrams.
Thanks. I think that will do the trick.