rinse aid solenoid
My apologies, I lost track of this thread. If you haven't tested your solenoid/valve yet, look on the wiring diagram that should be glued on the inside of your door panel.
I have only had the later models' of the Reverse Rack, and they had 120 volt solenoids on the dispenser. I suspect yours does too, but check the wiring diagram to be sure. If there is no wiring diagram, trace the wires and note if they go directly to the timer. If so, it is a 120v circuit, as you have no transformer present in your machine. (The operating voltage may be stamped on the solenoid itself, anyway.)
On the later model Reverse Racks, Maytag ran the detergent dispenser in series with the heating element. The resistance of the element lowered the voltage for the bi-metal heat/operated release latch in the detergent dispenser.
If your dispenser solenoid is 120v, momentarily connect it to line voltage and see if a couple of drops of rinse agent are released. If not, you may have to clean the nozzle with a large needle and/or attempt to clean the valve body.
By the way, I grew up in a house that was built in 1954, which had a septic system AND a water softener. My parents had it installed when the house was new. Later, two of my own homes were on a septic system and I had a softener installed.
There is zero effect, absolutely zero, of a softener affecting your system in any way. It tells you this when you read the softener's instruction/installation manual. I can confirm with many decades of experiencing softener on a septic system that it does nothing derogatory, in any way. You won't even know its there.
In the long run, in may help your septic system, as you will greatly cut down on the amount of detergents you use, as soft water requires lesser amounts. You will also not be using the harsh chemicals to clean your fixtures (faucets, sinks, tub, shower stall, etc.) as they will have no longer hard water or soap scum deposits occurring on them.
Barry