Typical Stereo Draw in amps and 24v wiring?

[RedMist]

I have a dilema. My Hino truck (used for carting the race car around) has a very crappy 24 volt stereo in it. I purchased a 12v stereo thinking that the Hino would have the typical 24v/12v converter installed and a stock 12v stereo... tis not the case. My crappy stereo is 24v and no converter exists.
As such I need to know approximately what a reasonable head unit with 2 x 4 inch and 2 x ( 6 x 9) " will draw?
Secondly as the stereo typically has two 12 volt feeds and I only wish to purchase one converter how do you recommend I wire it?

[Alex B]

Can you not just go off one battery? Take the acc feed off your constant 12V feed and run it through a 24V relay from your 24V acc switching source, if that makes sense to you. Head units are usually fused for 10A so I guess you would say 15A to be on the safe side.

[Mr.Phreak]

Depending on what you're wanting to spend, I'd go for a 15-20A unit, the price gap generally isn't too big and it gives you a bit of flexibility if you wanted to add 12v cigarette sockets or add any other 12v unit in later.

[RedMist]

Can you not just go off one battery? Take the acc feed off your constant 12V feed and run it through a 24V relay from your 24V acc switching source, if that makes sense to you. Head units are usually fused for 10A so I guess you would say 15A to be on the safe side.

I looked at doing something similar for my winch. However on investigation there is no way to balance the charge again. You end up destroying one battery.
So something like this? http://www.trademe.co.nz/Browse/Listing ... =168862677. At least if it overheats it drops output to 1amp only.

So how do I wire it? Perminantly wire it and manually switch a second 12v source for on off?

[Alex B]

Something like that, is how I would do it. Excuse the ranginess

[RedMist]

I saw it something more like this... although I know nothing of electonicty

[Alex B]

bad link for me

[sprey1661]

our truck has a 24-12v converter its a nissan 8x4 , i guess i could get a pic of the wiring setup for you ?

just running a sony stereo with 2 speakers

[Alex B]

Thats basicly exactly the same as what ive drawn from what I can see. I just haven't shown the 24V coming into the converter.

[RedMist]

our truck has a 24-12v converter its a nissan 8x4 , i guess i could get a pic of the wiring setup for you ?

just running a sony stereo with 2 speakers

Would be fantastic!

[RedMist]

Thats basicly exactly the same as what ive drawn from what I can see. I just haven't shown the 24V coming into the converter.

Sorry couldnt read most of yours. It's good to get confirmation as I have no idea as to wiring.

Just had a response to a question on a 24 - 12v converter on trademe. He stated that a 6 amp draw equates to about a 40watt stereo. Doesnt sound like its going to be enough to run it. Next size up costs as much as the entire stereo did!!!

[Bling]

I could be way out here, but is it possible to run a 3rd battery thats dedicated to just the stereo / future 12v stuff. Connect it up to the alternator some how to keep its charge up there. Leave it seperate from the rest of the truck tho....hmm probably not...

probably not as simple as that, but could be possible with some work?

just an idea anyway

[RedMist]

Cant charge a 12volt battery with a 24v charge. Will need to create an additional alternator mount, alter belts, additional battery, wiring, etc. Looked at doing something similar for the winch, but it was cheaper to purchase 24v

[matt dunn]

you can get two channel reducers, they have a 10A and a 2A circuit,
so you dont keep loosing the memory.
I can remember the part number but not the price from work sorry.

Hope you either have a master switch on the truck or you use it at least once every 2 or 3 weeks, or either option will cause flat battery drama's.

A common problem we get all the time,

and running a power source off one battery is a good solution for a few weeks, but long term will cause nothing but headache's.

[sergei]

Cant charge a 12volt battery with a 24v charge. Will need to create an additional alternator mount, alter belts, additional battery, wiring, etc. Looked at doing something similar for the winch, but it was cheaper to purchase 24v

You can charge battery with 24v supply, just stick appropriate regulating circuit (1 Power transistor, and bunch of small stuff, depending if you want to current limit or or just voltage limit the 12v charging system).

[MAGN1T]

As above, the proper reducers have 2 outputs.

The current draw is proportional to the sound output.

2 amps at 12 V is usually loud enough. A 5 amp reducer will supply enough current for plenty of noise.

Steve

[matt dunn]

As above, the proper reducers have 2 outputs.

The current draw is proportional to the sound output.

2 amps at 12 V is usually loud enough. A 5 amp reducer will supply enough current for plenty of noise.

Steve

Correct, but be careful as some units draw quite a lot while loading/unloading CD's etc etc as the motor to move all the mechanism take a bit.

The older tape decks, with electronic loading are the worst.

[sprey1661]

sorry im a bit late with the pic will try 2mrw!

[RedMist]

Sorry Gentlemen, picked up this unit yesterday http://www.trademe.co.nz/Browse/Listing ... =168482640

Sounds like I should just wire it to the ACC feed and forget about the memory on the radio. It'll spend a majority of its life in poor radio coverage areas anyway. I might even loop it off the race car RT for pit work.
DUH... there goes another 12 volt device I need to wire up!!

[matt dunn]

Sorry Gentlemen, picked up this unit yesterday http://www.trademe.co.nz/Browse/Listing ... =168482640

Sounds like I should just wire it to the ACC feed and forget about the memory on the radio. It'll spend a majority of its life in poor radio coverage areas anyway. I might even loop it off the race car RT for pit work.
DUH... there goes another 12 volt device I need to wire up!!

Yeah, but you will need to power both the feeds to get it to work,
which will mean that every time you turn on the key or start the engine,
it will cut the acc feed and the cd player will spit out the cd as they all do when power is first applied to them.