# Arduino water pump with relay not working [closed]

I'm trying to make a water pump work with arduino but I have a problem, it doesn't work and I don't know why. I'm a beginner with arduino so there are a lot of thing that I don't know.

I'm using a relay and a external energy suply, a battery, because I know that the arduino cannot do it by itself.

The conections in the relay are:
INPUTS

• DC+: positive power supply (VCC)
• DC-: negative power supply (GND)
• IN: Digital 9

OUTPUTS

• COM: Battery +
• NC: Water pump

And finnaly I have the water pump connected to the Battery - and to the relay (NC).

Here is an image:

The code I'm using is this:

const int control = 9 ;

void setup()
{
pinMode(control,  OUTPUT) ;
}
void loop()
{
digitalWrite(control, HIGH);
delay(2000);
digitalWrite(control, LOW);
delay(1000);
}


Can anybody help me please? I'm in a hurry and I don't know what else to do.
Thanks beforehand.

• Do you hear the relay click when you put your ear close to it? May 22, 2017 at 14:38
• That looks like a PC Fan connector, which usually requires 12V, not 9V. (if that is a pc watercooling pump) May 22, 2017 at 14:41