some question about windshield wiper motor

[zbrocket]

I tried to do every possible things to fix this problem, I am out of luck.
Problems are a) When I try to use the window washer by pushing the washer button located at the leftside of a handle, it works totally fine first time. But, when I push the real window washer button, then try the front window washer buttom, the washer does not come out! I can't hear any pumping motor sound. the real window buttom works fine.
b) If I try to use the real/front(not working any conditions except for the first time after replacing the washer pump), washer buttom without starting the car, the motor pump does not respond at all.

I thought it was a problem of washer pump, so I changed to a brand new one. But the problem does not vanish. a guy said my battery seems pretty low. I am not really sure whether the wire connection of a washer pump between the front and the real has some problems or it is a problem of my battery. I am so frustrated! Any comments are welcome!

My vehicle is Explorer 4.0 SOHC 1998

 

[zbrocket]

I am just adding another possibility, the possibility that the fluid pump button switch is dead?