Electrical problems

[kslim]

Hey Guys,

Just got a problem which some of you might have the answer to.

This is regarding the installation of a head unit.

I have no constant power wires behind the din, I only have the acc wire. Can I run another wire striaght from the battery to the head unit as a constant power (with fuse) ? Or will that drain the battery?

Another question that I've got is how do you make another Acc power supply? I want to use if for fog lights

Any help would be awesome.

Cheers

Kslim

[Guest RedLineGTR]

you can run it from directly from the battery just make sure when you shut down the ignition off you turn the deck off...

[Guest RedLineGTR]

some people have done it like this so they can just run the stereo with the keys. The proper way is to get it to work when there is igniton. I rekon the battery thing is abit bodgy, but your choice

[kslim]

"you can run it from directly from the battery just make sure when you shut down the ignition off you turn the deck off..."

So does that mean that the head unit will turn on with out ignition??

I thought it wouldn't turn on without ignition because I can use the ACC power supply thats there...??

thanks

[Henros]

Dude, running a fused wire from the battery is fine. The head unit shouldn't turn on without ignition, because the direct 12V line is only there to power the memory circuit so you don't lose your settings. Main power for the head unt is drawn from acc.

[kslim]

Sweet!! Thanks Henros

You wouldn't also happened to know how to create another ACC power supply would ya??

cheers buddy

[Henros]

To create a new acc line from the existing one to run heavy current devices, all you need is a relay. See attached pic for wiring details. Since the middle pin (normally closed contact) is not used, you can use a single pole single throw (SPST) relay. You can get an 30A SPST automotive relay from jaycar for 6 bucks. A matching socket with cables is also available for $5.90.

Cheers.

[kslim]

Is there another way to created it because the exsisting ACC i have used for my head unit. So I have no exsisting ACC..

Or can I connect the ACC to both the relay and head unit?

Thanks in advanced

kslim

[Henros]

You can connect the existing acc to both the headunit and the relay.

[kslim]

Thanks Henros

Have a good nite mate

cheers

kslim

[BOoStEr]

It is best to always wire the permanent power wire (usually the yellow wire) directly to the battery using a decent gauge wire fused as close as possible to the battery because most of today's high powered headunits use this wire for their main power. the acc. wire (red) is only to turn the headunit off when you turn off the acc.

[Henros]

mmm, come to think of it, that makes sense Booster. The acc is merely an "enable" wire rather than the power wire.

[advance]

the acc acts as a turn on wire for the headunit. It is much the same as a remote wire from a headunit is to an amp, it tells it when to turn on so the amp isn't drawing power from the battery when the car is off.

if you are running a headunit and you intend to use the internal amplifier (eg. run the speakers off the headunit) then i would recommend running a new fused power wire directly from the battery. However if you just intend to use the RCA outs from the headunit to run an external amplifier it probably isn't necessary to upgrade the power wire and you can usually just split a wire off the cigarette lighter. (be sure to do this safely).

If in doubt, run a new wire:)

[kslim]

hmmzz.. very interesting, this is all starting to make sense now!!

hahahah LOLz.... I'll be a pro in no time!!