how do you wire up for three amps with 1 turn on wire on Headunit. do i brige it or run 1st to amp and 2 from 1st amp to 2nd and 2nd amp to 3rd amp?

 

You can just run a wire from one amp to the next and then to the head unit.
If they don't start up you may be running too much current from the remote output of the head unit, if so you need to wire a relay.
My head unit runs three amps with no problems though.

 

Thank you. I am running 18 gauge wire is that good enough or do i need 14 or 16 gauge

 

you can run 16 gauge, but 18 should be fine. the main concern isn't how much current the wire is handling, but how much it's drawing from the deck. like xsi said, if it doesn't work, just run the relay.