relay in remote turn on

If I am going to hook up several amps and fans in my car I want to use a relay. Here's my question. I believe the remote turn on wire on most decks is 5v, is this correct? and if so, is it bad if i have 12 v running through the relay and hooked up to the amps to turn them on? are they only designed to take 5v? Thanks guys. "Screw nitrous, I'd rather be blown."

Your RCA's have 5 volt output , but your remote wire has 12 volts.  It can be confusing, but that's OK .... You should use a relay when controling 2 or more amps due to current draw to keep them on.  to wire your relay just take your remote wire from the radio to pin 86, ground pin 85, connect ignition to pin 87, and finally use 30 to go to your amps .... hope this helped you out..  also please fuse the ignition and your remote wire form the radio to prevent damage ,   I would use a 5 amp for the remote and a 10 amp for the ignition wire.

Thanks for the help Dayz. Just one last question, are you saying I should either hook my relay up to the ignition or the remote from the deck? Just pick on at random? Thanks in advance."Screw nitrous, I'd rather be blown."

Thanks for the help. Just another quick question, in addition to the fuses, do I want to put in diodes at all? also, what size connectors do i want to buy to fit on the relay pins? and one more....How, if you have pin 87 hooked up to a +12v all the time, is it heating anything up or drawing any power if it isnt connected? Or would that just be an ideal relay and non are actually that efficient? Thanks again.... Very greatful, Mr. "I didn't think it was this easy to cause a fire...""Screw nitrous, I'd rather be blown."

What I mean by what size, which one of these will fit on a relay? http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CAtid=41&ObjectGroup_ID=400"Screw nitrous, I'd rather be blown."

do relays use 1/4" male tabs?  why does the remote turn on need a fuse. i've never heard of that. just curious.