Thanks for the info regarding the fire hazard. I printed out the recall notice from CPSC's web page. I will provide it to the owner as their model & serial number falls within the sequence.
So. after reading the latest advice, I pulled the machine out of the cabinet, removed the pressure switch and vacumed a whole lot of mouse debri from around the styrfoam disc. When I was done the disc could spin freely and there was no evidence of any dirt remaining. I reinstalled the pressure chamber, moved the red rod up & down a few dozen times and put the machiine back under the counter. No change in dishwasher performance. I checked to see if the new inlet valve was getting current with the machine on and "humming" and it was.
If the float switch was causing the problem would the inlet valve still be getting current?
I can't see any standing water in the plastice base, where the float switch is, nor is there any evidence that water has been leaking from the tub.
I hope to be allowed to stay with this until I get it done but I do seem to be chasing my tail. Suggestions?