Electrical / ICE Expert Needed - Advice Please!

[stretcho69]

ok. Im in the process of doing an install in my 172 at the moment. So far i have installed new speakers all round, set of 6x9's in the rear powered by alpine amp which runs directly off the battery. Have also uprated all the speaker cabling for better sound!

Next stage is to install an Lcd screen up front which i will custom build into the dash. Question is, what kind of wiring do i need to support relevant current from the screen? I also have 2 other 5" monitors which i may well build into the headrests.

I have purchased a signal splitter so all 3 screens will run from the headunit.

Just need some advice on the best way to wire all this up?? what type of cable to use and the best way to get the power through?

Soz for long post, any help would be great!

 

[cliocc]

Well the best way to choose wiring is to look at the current draw from the screen on the back label or in the instructions. Most stand alone screens I’ve come across don’t need much more than a couple of amps. So 16awg wire is good enough.
16awg has a max of about 3.5Amps
14awg has a max of about 5.5Amps
12awg has a max of about 9Amps
High quality cable may be able to carry more however longer lengths of cable can reduce the current carrying capacity. Neither of which you really need to worry about buying normal automotive cable in the lengths needed for a car.
Running the cables is best done from the battery as with multiple items running at the same time, to try and tap this off an existing circuit in the car could put that circuit under too much load and burn it out or at least burn the fuse out. So run one main wire from your battery to a fused distribution block and then from the individual fuses to the screens. You may as well run this along with the cable going to the amp untill behind the dash. Remember that this wire needs to be capable of supplying all loads simultaneously. For example 3 screens each drawing 2.5 amps would need a cable capable of 7.5Amps, so 12awg would be used.
As for visual signal, the better the cable, the higher the chance of getting the best possible picture. You get what you pay for here. Also keeping the cables only as long as they need to be will reduce the chances of picking up interference, as will running them to the head unit along a path not shared with any other cables.
Turning to the signal splitter. Keeping it closer to the head unit is better as the shorter cable run between source and splitter will reduce the chances of picking up interference and sending it to all three screens. If the splitter also amplifies the signal to the screens then this is even more critical. Try to run the visual cables for the headrest screens down the dash to behind the gearstick and under the carpet from there to under the seats. This route should have the fewest wires around to give interference to the screens.
Best of luck and hope my ramblings help.
C

 

[stretcho69]

excellent info thanks mate, very helpful