12v relay board

i have been working this for a bit now i got the diagram from seller hooked it up as shown
and fried my adruino…

can someone help me out i think the issue is i need a diode some where but have no clue where or if i need any other components

this board will be used to control various things in my car such as the hvac system

attached is how i hooked it up

thanks for any help
and if its not obvious im new to electronics

Might we ask for a bit more information about your relay board? A link to the datasheet might appease our curiosity.

1) That is a very poor image 2) It tells us nothing about the function of the relay board pins

How about this:

1) Give us an actual schematic or link or something so that we know exactly what and how the board is supposed to be hooked up 2) A picture of your actual, physical setup, showing the connections clearly 3) A link to the vendor's site for the board, or a name/model, etc


here is a link to relay board i have

sorry about the images quality it was a screen shot I have attached the cad file and the information i have from the seller

I believe I have the wires connected correctly i just think im missing a diode some where

relay_setup.dwg (50.7 KB)

1 Like

Ouch. I'm not surprised you blew your arduino up. 13.5v straight into the IO pins... pop.

It looks like the power connector where you connect the 13.5v is connected wrong.

As far as I can tell, from the left, pin 1 should be ground, pin 2 should be Arduino 5V, and pin 3 should be 13.5V.

The pin 2 (Vcc) connection goes through the optocouplers to the IO pins. They need to be driven LOW to turn ON the relay ("active low"). The Arduino sinks the current through the optocoupler. The other side of the optocoupler then switches the higher voltage to the relay to make it activate.

You might well have blown the optocouplers as well.

i missed a few

8 Channels 5V Relay Module Schematics.pdf (346 KB)

thanks for the reply i just want to make sure im understanding you correctly
here is an updated cad and screen capture file

will this work or am i still not getting it

relay_setup.dwg (50.8 KB)

That looks like it should work fine.

sounds good ill give it a go


that worked perfectly thanks for your help