I am restoring a San Marco 85-16M-2. It was left somewhere and mice had got in and chewed through many wires. after many replacement wires, |I have got it up and running with one problem.
the left hand group works as expected. The right hand group does not function. When a button is pressed on the control panel for the right hand group, the backflush light on the left hand group lights up. The right hand group does function when the manual button underneath by the pressure gauge is used, so the wiring to the group solenoid is functioning.
one of the wires i had to replace was the ribbon cable that links the two group control buttons, i have rechecked them and all seems well. I am wondering if the backflush light illuminating is like a fault code on a car and means something?
If anyone has any clues, I would like to hear your solutions.
Ian

I have often found it helpful to draw a wiring diagram. It doesn't need to be fancy, just legible in that a person can follow which line goes to where. Colour code them. That alone can help you see something you've missed - kind of like proofreading backwards and slowly. If that doesn't help you, then post your drawing here.

-phillip

I will try and look up a wiring diagram. I was thinking that the lighting of the flush button on the left bank of switches when a button on the right was pressed,was a fault indicator.