Memory is a wee bit fuzzy, but the diodes are to separate the solenoids from the motor relay, it is a cheat way to get "two to do one".

The way the Bennett pumps work is a solenoid opens when the motor runs and closes when the motor is off, there is an up and a down solenoid, but only one motor which reverses polarity, that is where the diodes come in, I have a diagram on my other 'puter, will get it fired up here soon...


GT