Since it is an intermittent issue, you might try taking a volt meter and measure and record a selection of voltages around the engine bay and under the dash to get an idea of what the normal condition is like. Then next time it acts up, re-measure those same points and compare the numbers to normal. Find test points that would let you check the voltage on various circuits so you can try and find some root cause of the issue. And try tracing out all the affected devices on the FSM wiring diagram and see if there are any common connections or points upstream of them.

Yep, that steering wheel pulling tip has been a face saver for me, heard it a long time ago and have used it ever since.