Wiring Help!!

Hi 12 Volters!!!

I have a problem.

I have a 1 DIN in dash TV unit, a 1 DIN DVD player, and a AM/FM TV tuner amplifier. All need seperate power supply's

I am ok with the wiring apart from where to get the power from.

Do I connect the 3 power supplys to the power behind the old radio unit? Or the battery? (I have heard this is not the best option as can damage TV or DVD or tuner.)

I have also been told not to go to the ciggy lighter as this is on the same circuit as the main radio power.

I think I have heard too much conflicting information.

I am hoping to get it all in in the morning. Also I am installing a couple of headrest monitors soon, so any work regarding power I do now, I would have to take that into consideration.

You can connect them to the battery, you just need to put a fuse in between the battery and the component to protect the component if something shorts out.  If you don't put a fuse in there and you short out one of the power wires, it'll probably fry one of the components.  But still I would recommend going to the battery instead of tappinh in to existing wires under/behind the dash because those existing wires probably wouldn't be able to handle the extra current draw.

Try to find the specifications for each component and see what the "maximum current draw" is.  Each component should have a fuse on its wire that is just slightly above its maximum current draw.

Rather than run 3 wires all the way to the battery, It'd probably be better if you used just one 12 or 10-gauge, fused (add up the rating of all the components' fuses) power cable to run all the way to the battery.  Once you've run the other end of this wire to a spot near the components, you can hook up each component to this one battery wire.  Just make sure each component has its own wire coming off of the main feed, and that each wire is properly fused as I described above.

Cant see "maximum currend draw" The screen has "operating current" of 1.5amp (nominal) the tuner/amp has "current consumption" 7.5A (nominal. The DVD player is at my mothers so not too sure about that one.

For some reason I forgot that many components come with a fuse already built in to their harness.  If this is the case for any of your components, you obviously don't need to add another fuse on its power wire.  But still you need the main battery feed to have a fuse.

Now if each component doesn't have its own fuse, use a 5amp fuse for the screen, a 15amp fuse for the tuner/amp, and a 10amp fuse for the dvd player.  Obviously if you find a current spec. that says 2amp (nominal) then just use a 5A fuse, but I'm basing my reccommendation on what similar DIN dvd players are rated for.

A lot of times they tell you what size fuse you should place on a power wire for a component,in the user manual or installation manual.  I dunno if you have access to those or not but I'd check those before adding in your own fused wires.