Where to Power

[Peco 10+ year member]

Im hooking up a Navigation system, Rearview camera, and a Touch Screen DVD HU to my car where should I run my battery power wires to? My HU I know can be connected to the factory wiring harness but im not sure where to hook up the Nav. and Camera power wire. And for the ACC (ignition) im just going to tap into the fuse panel. I was thinking of running all my power wires to the HU but that wire is to small to power everything.The camera has a Max. current consumption of 150mA and the Navigation Current Consumption of less the 2.5 A. Also both have fused wires Camera 2A and Nav. 3A. Should I just run a power wire from the battery?

Click to read more...

 

[ace_800 5,000+ posts]

Find a "hot" power wire behind your dash and tap it. They will work fine.

 

[Peco 10+ year member]

Find a "hot" power wire behind your dash and tap it. They will work fine.

So you don't think I should run all to the HU wire. Could you throw out a few ideas as to what "hot" power wire? Could I run all 3 wires to the ACC?

 

[kross 10+ year member]

The same wires that power your HU, can power your nav and camera as well.

 

[starkfu 10+ year member]

run a 10 gauge wire from the battery to the HU, then use the factory harness power to power the various things you have running.

 

[Peco 10+ year member]

run a 10 gauge wire from the battery to the HU, then use the factory harness power to power the various things you have running.

What kinda fuse should I have for the 10g wire that goes to the HU?

 

[CrazedCat 10+ year member]

any inline fuse 30a or 25a

 

[starkfu 10+ year member]

I would use 15 amp, to match what most factory feeds have. The point to going to the battery is to reduce noise in your DC voltage feed. Also make a new ground to the firewall for the HU.

 

[CrazedCat 10+ year member]

If he's running his own power wire he needs to fuse according to the gauge of the wire he's using... not to match other factory leads.

 

[starkfu 10+ year member]

no, the fuse should be matched to the current draw of the components you are running that fall under the max rating of the cable. So where 10 gauge can HANDLE up to 25-30 amps, you don't fuse it for that, you fuse for what you are running off of it.

So a head unit is usually fused at the factory at 15 amps. You don't put in a 30 amp fuse for a 15 amp max draw piece of electronics. You put in a 15 amp. Otherwise you run the risk of blowing up your electronics if they short or malfunction. Where a 15 amp fuse would blow and protect the electronics, putting in a 30 amp fuse would ensure that the current rating threshold would be surpassed and damage will occur.

Conversely, if you are running an amplifier off of 4 gauge to the battery, and the amp has 4 20 amp fuses, you don't put a 150 amp fuse at the battery, you put an 80 amp fuse.

 

[CrazedCat 10+ year member]

He states that he'll be powering other accessories as well.

 

[andytb 10+ year member]

if you run it direct to battery it would stay on

 

[andytb 10+ year member]

i know a neon the red/white is what the ignition wire for the hu is

 

[starkfu 10+ year member]

but the point was to isolate the radio power from the accesories.

So the accesories grab their 12 volt constant from the factory harness, the radio grabs it's 12 volt constant from the battery isolated from anything else drawing off of the wire.

The radio won't stay on all the time because you will still have the 12 volt switched wire hooked up from the factory harness. I am merely suggesting that the BEST way to do it is create new ground and +12 volt constant connections independant of the factory cabling for the HU.

 

[CrazedCat 10+ year member]

Probably the easiest thing to do is get a Littelfuse "add-a-circuit" and plug it into an unused switched hot lead in the fuse box.

Just get a 12v test light, switch the ignition to ACC and find which fuse slot is a switched lead. (just confirm it doesn't light up when the ignition is off.)