Thread: Battery <-> PSU

Originally Posted by Karma

Before anything, just letting you all know that I did search for this information. I didn't scour every thread and post made on this forum but I believe I searched well enough for this information. Anyway, having said that...

I've been learning about doing this for a short time now. I do, however, have no experience with car wiring systems. At all. Currently my car doesn't even have decent speakers, it has stock speakers still, because I don't know how to put the speakers in and wire them up.

So yeah, you know I'm a car noob now. My question relates to the connecting of the PSU (I had the OPUS 150w in mind) to the battery. Now, the comments on the forum are very vague about this and it's never really explained. It's probably taken for granted that everyone knows what you're talking about and maybe they do. I don't. From the way this aspect is described it sounds as though I need a direct line from my battery to the PSU, another direct line from the PSU to part of the chassis for grounding...but I don't understand why and honestly I think that sounds incorrect given how..impractical it all seems.

Now, I'm aware that behind my CD player and such are a bunch of wires. These are the wires currently hooked up to my CD player and power it. What's to stop me connecting these wires to the PSU? They supply power, and there would have to be a ground wire there aswell, I presume.

So, when talking about connecting up the PSU for power, are you all actually referring to these said wires, or am I going down to the store to aquire some form of wire to create a direct line?


I apologize in advance if this is either too stupid a question or has been asked before.

Yes you have to connect a wire to cars chasis(the chasis is the ground) And yes you have to connect to the battery, the wires for the radio are too small so they have a maximum of current that can pass in them. You can do it , but they will get hot, blow the fuse, catch your car on fire(this is the worst that can happen). And yes you have to buy wires to connect the Psu to the battery and body.

Originally Posted by kevinlekiller

Yes you have to connect a wire to cars chasis(the chasis is the ground) And yes you have to connect to the battery, the wires for the radio are too small so they have a maximum of current that can pass in them. You can do it , but they will get hot, blow the fuse, catch your car on fire(this is the worst that can happen). And yes you have to buy wires to connect the Psu to the battery and body.

Thanks for the quick reply.

Since I've already got a thread on the subject I may aswell keep asking here.

This thread in the FAQs section briefly describes the process, however it does not suggest what kind of wire should be used. If it's too thin, it heats up too fast, right? So what gauge of wire (if it's called that) am I looking for?

There's already a wire/connection on the battery. Do I need to do all possible to avoid the wire I attach touching this or does it not matter? Also, what would a safe and reliable method be for connecting this said wire to the battery so that it won't remove itself?

This thread also talks about wiring the PSU to the 'IGN' fuse, or more correctly, it says 'tap into a fuse'. I don't understand such a technical term as 'tap into' . I'm guessing I run a wire from the PSU and jam it between the fuse and its connector on one particular side. If that's correct, I assume there's a simple method for working out which side of the fuse I should 'tap into'?

Finally, when setting up the grounding wire...are there any pros or cons to taking it back to the battery? What I mean is, would taking it back to the battery be more efficient or likely to work properly than locating or creating a bare metal section of the chassis to connect it to? I've read about people having buzzing issues related to the grounding of their equipment and wondered if my chances of meeting this problem would be reduced or the same if I ran it to the battery.

You seem like you need a basic guide to wiring with an emphasis on car wiring. You might try the faqs over at the12volt.com they address all types of car installs from basic to ultra high level show only stuff.
Good luck

I would suggest an 8 guage amp kit. This comes with a 15-20 foot length of wire. And a 4 foot or so length of wire to use as the ground. As for connecting to the battery there are many methods. Main ones are for you to use a crimp connector on the end of the wire and then place this on the battery terminal. This is only if your battery has screw type leades.(ie most pontiacs). The other way is to use a battery terminal that attaches to the battery post. This allows you to attack this driectly to the battery post and attack you amp wire along with your car excisting wiring. You will also need a fuse within 18 inches of the battery for your positive line. This is included in a amp wireing kit. Here is an example amp kit. http://www.cardomain.com/item/STISWK8
The connector on the end of the wire is a crimp ring terminal to connect to screw on batteries.
Here is an example battery terminal that connects to the battery post.
http://www.cardomain.com/item/LITBCMOP1

Hope some of that helps.

And btw: it is not neccessary to run the ground back to the battery unless your car is extremly old and the elctrical system is horrible. A clean piece of metal provides a more than adiquite chasis ground.

Originally Posted by Simon123

You seem like you need a basic guide to wiring with an emphasis on car wiring. You might try the faqs over at the12volt.com they address all types of car installs from basic to ultra high level show only stuff.
Good luck

Thanks a lot, this should help me understand a little better where everything goes together

Originally Posted by Jcarere

I would suggest an 8 guage amp kit. This comes with a 15-20 foot length of wire. And a 4 foot or so length of wire to use as the ground. As for connecting to the battery there are many methods. Main ones are for you to use a crimp connector on the end of the wire and then place this on the battery terminal. This is only if your battery has screw type leades.(ie most pontiacs). The other way is to use a battery terminal that attaches to the battery post. This allows you to attack this driectly to the battery post and attack you amp wire along with your car excisting wiring. You will also need a fuse within 18 inches of the battery for your positive line. This is included in a amp wireing kit. Here is an example amp kit. http://www.cardomain.com/item/STISWK8
The connector on the end of the wire is a crimp ring terminal to connect to screw on batteries.
Here is an example battery terminal that connects to the battery post.
http://www.cardomain.com/item/LITBCMOP1
Hope some of that helps.
And btw: it is not neccessary to run the ground back to the battery unless your car is extremly old and the elctrical system is horrible. A clean piece of metal provides a more than adiquite chasis ground.

And thank you, I wasn't aware that there were kits I could use to do this sort of thing. That's a real relief because I wasn't too confident about my wiring skills to buy just any bit of wire, hook it onto my battery, and then probably burn something. One of those kits would suit me to the ground.