Quick Wiring Question... (Easy)

Hey guys. i'm good with wiring and all but i have a simple question. Does it hurt for me to branch off of wire for power. Ex. i have a power wire running from my battery for my amp. but like on the back of my head unit we all know yellow is 12v or turn on. Well im getting ready to install LED's in the cab. would it hurt for me to tap the power for the LED's into my 12v turn on on the back of my head unit? it's like running two applications off the same power source. (Switch installed on LED's so they wont always be on of course) Just curious if combining such will ever hurt anything. Thank you for your time. i appreciate it

it depends on quanity of leds , the amount they will draw and the amount of load the current head unit draws and the size of the current fuse on the line

should i set up a small like 18 gauge wire and run it to my battery through the engine bay? Like an amp?

for the cold cathode kit (the basic 12" flowlighting cathodes) what is the mounting method advised?

Sorry to be a pain in everyones butt all i want to do is put two 12" cathodes under each side of my dash. Thank you

I'd suggest at least an in-line fuse bus for the second wire.

You do not need to run to the battery , you can use an add a fuse unit in the cab ,or tap it off any powered wire cigarette lighter ect

Cold cathodes can be mounted hundreds of ways depending on location ect ...
Silicone on the blocks hold them well to glass (windshield /side windows rear glass)
3M adhesive tape works well for smoth surfaces ...
Zip ties , always work... the type that has the screw hole along with the ziptie
People have used fishing line and sewed them under the seats ect