finally got the new RH pump installed,  and tractor back together.

The high pressure circuits that pump runs seems good-  Steering and  aux  valve  #2 and #3.  

The  low pressure side, however,   won't  turn off the  warning indicator on the dash.   When the computer 'sees' this, it won't engage the PTO,  Diff Lock, Range shifter.     The  speed shifter, however,   doesn't  go through the computer, and is working fine.

Thinking I had a bad  sensor,  I jumpered that plug with a wire..  no change.
I ohm'd the switch.. It's open when tractor isn't running,   closed when it's running.. as it should.   So it's  definitely seeing pressure to actuate itself.  

Is this the  end of  my autotronic  days... and  need to  convert this tractor to a  more mechanical type... like my 3545
?

About all I did was  change the pump,   rebuild that axle housing,  and move some wires around to facilitate this process.   

Oh,  I did ohm that plug's  harness,  and it shows continuity.    Like  dead-short continuity between the 2 wires,  but  open from each wire back to ground.  

Edit to add-   Spent a little more time  'experimenting'.

I got the  computer to  boot up,  and  was able to  engage the other circuits.  

Both with the  jumper,  or  plugged directly to the sensor.  

I did it by   repeatably  hitting the  2 speed in and out rapid-fire like...  which  started making the  dash warning light flicker (in-time to me pushing the 2 speed button)   .. Soon as it  flickered,  the computer came to life.     But the light on the dash never went out.
Weird thing,  it shouldn't flicker at all  with the jumper installed,  and the dash light definitely should be out.
------unless there's another  sensor somewhere I'm missing------  I'm aware of only one on this low pressure circuit-  or there's a  bad 'switch' in the  brain box.

Shut the tractor down,  and  I had  to do the dance again to re-light the computer.     
The electronics  worked ok  before the pump went bad,   I'm thinking the severe power washing I did around that side of the tractor got moisture up in the brain box.   (why did they put it in-line with the rear tire)???  geez.  

So unless there's  a  sensor somewhere else giving a bad command,  I'm probably going to run a  keyed  circuit that  powers these solenoids.   I'll get the 3545 type latching buttons for the  diff lock, and 4wd,     probably have to  put in a heavier switch for the PTO,  and run stand alone circuit to each  solenoid.

Not sure how I'll wire up the range shifter,  so  the rabbit lights up when in high,  turtle in low..  have to do some head scratching on that first.   might have live without an indicator.   All I know is the shift tower hits a momentary switch,  causing the computer to either turn on or off the actual shifting solenoid.. and lights up the appropriate  indicator on the console.