All you need to do is grab a basic car 12v 30 amp relay, some inline fuse holders (preferably weatherproof), appropriate sized fuses, heat shrink, flux, some solder and female spade connectors and bust out your soldering station and wire it up.
The relay follows a basic layout. 4 prongs and each prong represents something different on the relay. They are labeled as followed:
Prong (30)---12v power from battery
Prong (85)---Ground
Prong (86)---Lead from switch (amp turn on signal in)
Prong (87)---lead from relay (amp turn on signal out, going to amps.)
What I did was ran a 12g wire from my battery to prong 30. I soldered and inline fuse holder and ring terminal on the one end and a spade connector on the other. I fused it with a 30amp fuse.
I then placed the relay where I wanted it in the hoe. For me, I placed it under the cup holder in the center console. Some people dont like to hear the clicking of the relay turning on but, it dosent bother me.
Once I was happy with where it was placed I cut another length of 12ga wire and ran a ground. This wire had a smaller ring terminal so it could be grounded out with a self tapper. The other end contained another spade connector to hook up to the relay. (I didnt ground it just yet)
From there I cut the amp signal wire (Blue turn on lead) and wired on a spade connector to that. I also wired on a spade connector to the other end of the freshly cut signal wire.
If you want to, you can add in another inline fuse from the amp signal wire going to the amps for extra protection. This wire draws so little current that I wasn't worried about it and excluded this step. If you are wiring in many amps then, it is recommended.
So, once you have all your wires labeled and properly soldered up ground out the unit and plug in the other 2 signal wires. Make sure you have your connections following the above diagram. As long as you make sure you have the Power wire and the ground in the correct positions but, your amps dont turn on its only 2 wires left, just switch them and you should be good to go.
I have the relay turning on only 3 units in the truck. An equalizer, a 1200 watt amp, and a 1000 watt amp. Works perfectly.
I also literally knew nothing about relays and picked this up watching youtube videos. It is very simple, once you understand it of coarse.
Good luck!
Regards,
J