12v 4 chan relay module

i am trying to make led strips flash to music. i got a 12v 4 chan rely module i have 5v going to the vcc witch seems to power the bored good. i have signals going to the bored and the status led turn on and off right but the relay makes a little sound but does not trip. i guessing i need to hook 12v to the board?

What's to guess?

I have a petrol engined car. I put diesel in and it won't run. I'm guessing I should use petrol?

So many relays really should have thier own PSU with a common ground back to the Arduino.

ballscrewbob:
with a common ground back to the Arduino.

Not all though, and the OP hasn't described his: it may be an opto-isolated one where the Arduino connection is only 5V and a digital pin to control the led in the opto with no ground, and it would then have its own power for the relay coil, even if the latter is a 5V one.

Odd as some of mine are 5v rated opto isolated modules and dont/wont work without the ground.

ballscrewbob:
Odd as some of mine are 5v rated opto isolated modules and dont/wont work without the ground.

Depends if the Arduino 5V Vcc powers the relay coil or not. If you want the Arduino 5V to power the relay coil, then yes you'll need the ground to complete that circuit. But then you're not really isolated anymore. If the relay coil's 5V is separate from the Arduino, then no ground to Arduino is required, since the opto's led is between Arduino 5V and an Arduino digital pin active low: just like any other led.

But that all said, nothing beats looking at the circuit diagram of the relay board (or bored as OP calles it :wink: ) and therein the problem: sometimes finding one is the tricky part.

Many of them are like this, but not all.