Confused about Relays!

[Brian McVickers]

Ok, so I bought a ralay for my new lights and wired it in.
Tab #30 is hooked direct to the battery with an inline fuse.
Tab #87 is hooked direct to the lights.
Another Tab on the relay is grounded and the last relay goes to the switch.
Both lights are gounded

Good news! -- the lights work!!

Here's the kicker - and the confusing part --
I think this relay I have is always on!? I thought relays were always off and need to be supplied power to turn on.
With everything wired up and the ignition on, the switch controls the lights to go on and off. As soon as I turn off the ignition, the lights turn on regardless of the switch being on or off, it only gets power when the ignition is on. Essentially the switch is providing power to the relay to turn it off. As soon as the ignition is off and the switch has no power to send to the relay, the lights come on!

Can relays be always on?
I think I need an always off type relay!

Oh, and it may help to know that I bought the relay in the automotive Alarms section of Fry's Electronics. Could it be that a relay designed for Alarms would be always on so that the Alarm activates as soon as the ignition is turned off? The package just says Automotive Relay, Single Pole, Double Throw, 30/40 Amp Contacts, made by ProLink.

Thanks
Brian
:safari-rig:

 

[Sharkman]

mcvickoffroad,

Is there any chance that the relay you have has 5 terminals? If so it can probably be wired in either a normally open or normally closed configuration.

Example: powering your lights between terminal 30 and 87 would be normally open, and between 30 and 87a would be normally closed.

Hope this helps,

 

[Brian McVickers]

Yes, it does have 5 tabs!
I think you solved it, I'll let you know!

 

[DaveInDenver]

Yes, it does have 5 tabs!
I think you solved it, I'll let you know!

Did you connect to 87a and not 87? The 5 tab relays have a normally closed and a normally open set of contacts. The NC would be closed until the relay is switched, then they should open. So since you hooked tab 30 to +12V hot (straight to the battery) and the 87a to the lights, whenever the relay is off, either by your manual switch of turning the ignition off, the contacts power the lights. Move the lights to tab 87 (no 'a') and I bet it works fine.

This may help:
http://www.the12volt.com/relays/relays.asp