mega and output voltage

hey guys have some issue with my project her the code

void loop() {
  Usb.Task();
  if(PS3.PS3Connected)
  {
    if(PS3.getButtonPress(DOWN))
   {
     digitalWrite(led_v1,HIGH);
     {
       digitalWrite(led_v1,LOW);
     }
   }
   if (PS3.getAnalogButton(L2_ANALOG) > 0 )
   {
	   digitalWrite(led_v6,HIGH);
	   delay(5);
	   {
		   digitalWrite(led_v6,LOW);
	   }
   }
   if (PS3.getButtonClick(TRIANGLE))
   {
	   digitalWrite(led_v1,HIGH);
   }
  }
}

if i use this "if(PS3.getButtonPress(DOWN))" my output voltage is 145,5mV
and if i use "if (PS3.getButtonClick(TRIANGLE))" my output voltage is 4,980V and this is when i use USB cable and when i switch to a dc adapter (7,5V 0,6A)
the voltage is the same i wouldn't bother wit this at all but im use now a 5VDC Relay and a LED 5V and i need fast 4,5V to enable this relay
and if i use deley() the voltage is i around 5V

At the top of this section, there is a sticky thread.
Please read it.

Adding to AWOL's advice, I suggest you disconnect the relay from the Arduino right away, and only reconnect it after you fully understand the issues in switching inductive loads with an Arduino and have the appropriate driver hardware. From your description it sounds as if you are connecting it directly, which can potentially damage or destroy your Arduino.

the voltage that i was measured was without the led and relay that was "clean" output voltage without any consumer between GND and my output pin 23