1985 f350 7.5 l electrical issue. Helpppppp

I’ll do my best to explain. First all lights work when ignition key is on. My heater also works at all variable speeds. Once my engine is on most of my electrical still works. But my reverse lights My heater blower and my turn signals do not work. Now my passenger side reverse light socket is beat up and it is what I was planning on replacing next. But would this cause my problems with heater blower and turn signals? I have checked my fuses and replaced my turn signal flasher. Any ideas would be appreciated.

Test ignition switch

Turn the ignition switch on.

Verify everything functions.

Open the hood, and jumper the two large terminals on the starter solenoid to operate the starter and get the engine running.

Now see if everything still functions.

If they do. replace the ignition switch at the base of the steering column.

Tester