My don't windshield wipers, car heater, directional signal lights work?

You can start by checking your fuses for the items that aren't working maybe is a bad fuse.

While looking at a wiring diagram, the only common thing in those items is common grounds. There are many other things that share the same grounds, so I don't know why just those items alone did not work, and the other things are working. They have different power circuits, accessory relay, and the ignition 1 relay. There again other things on those circuits will work, Will probably need to be tested by a technician.