I figured out part of my 91 vanagons problem but am perplexed by its
cause....

The Power Steering Unit has a 2 wire connection to the electrical
harness that crosses the back of the engine compartment.
It seems that one of the wires (red with white stripe) melted in the
harness.  The Cause of this from a arcing plug wire damaged when my head
gasket fried/blew 4 weeks ago.  more problems...

WHY does the ps unit have wires...is it a sensor?
where do these wires lead? 

Could this be why my engine is hard to stay running and start....The
heads were just put back on...it started to run fine...until the engine
became rough 50 yards down the road...I found the arcing plug
wire..replaced it...and still rough starting/running...now I found the
wire to the ps unit...close by to the bad plug wire. I hope I did not
fry my  computer chip?

johnm