yashiharu:
c) try connecting only UNO & pump, it works for 3 sec then both device off
And, what happened 6 seconds later? If it turned on, then done.
(I can't believe I just spent 15 minutes writing an answer trying to ask for more info and describing why certain configurations would cause it to -not- work, then something fell on one of these unknown 'G' gaming keys that I don't use on the kbd, and everything -I- just wrote disappeared.)
Regardless, before I write it again, what's the URL for that relay board? It's very unclear whether the V on the header strip is supposed to be an input or output. More about that later after I see the spec because it -may- explain a -lot- of the failures/oddities.
That 'c)' above, there are -more- ways to hook things up that -don't- work than do. If it worked then that's the one that worked. If you need/expect some other configuration, then describe what it was you did that caused 'c),' and what you -think- should be different and still work.