Trouble with relays

I haven't had a chance to use relays before and just two in tonight. I posted the amazon link for them here.

I'm using a 12v battery pack to power both the arduino nano (has a 12v to 5v step down in-line) and the 12v positive lead goes directly into the IN+ on the relay. Grounds are tied between the two and in the relay's IN- terminal.

I loaded up a simple sketch that writes a digital pin high and low (connected to the relay signal terminal) every 500ms and the led switches on and off on the relay, and of course the audible click is there as expected. I went to go hook up the solenoid that I was going to power from the relay and the relay was not activating the solenoid.

I tried a couple different things and concluded it isn't the solenoid by directly powering it from the battery pack. I busted out the multimeter and in continuity it makes a sound every time it should, when the led comes on on the relay. If I go into voltage on the multimeter it reads nothing across the whole output side of the relay on both the NO or NC terminals. I bridged the pins that keep the relay open and got nothing on either output either.

  • Amperage of the power supply should be about 1.5 times the max that the solenoid uses
  • The relay is written high an low for equal times, so it isn't just on for like a 1ms or something like that
  • Both of the brand new relays I got are doing the same thing.
  • The relay is rated at 5v switching and 150v passthrough

I would think that if the relay is being activated and deactivated no matter what other variables there would be, you would see some voltage output considering there is continuity.

Any ideas?

I can work on a diagram if that would help.

Thanks in advance!

Seems you forgot to connect power to the "C", common connection on the relay.


Yes a diagram would help. Particularly you need to show the wiirng around the relay and solenoid, as the arduino doesnt seem to be the issue.

Posting a diagram