My 90 multivan seemed to have a hi & lo speed last year, at some point
last summer only the loud or high speed has been turning  on (--the one
that scares people in drive threws).
I checked out Ken W's procedure at vanagain(jumpering at radiator sensor
with 3 connection plug).
Yes--the hi/loud speed terminal will turn on but the low terminal wont.
I have checked at the motor.  one brown ground. ok .  And this is what
puzzles me--two reds that junction together on the (plus)terminal stud
on motor.  I applied 12v from batt to each of the reds.  both run it at
High speed(as I then find out they are connected).
I am more familiar with a.c..motors than this d.c.
Bentley not very helpful.
What test steps should i take next.

Thank you,
chris c
wisconsin