M2-ATX 160W - Radio Harness vs Cig Lighter vs Direct

**bmbr** · 03-07-2006, 04:39 PM

Hey guys,

So I am nearing the point of installation in my truck, and I am trying to decide how I want to hookup my M2-ATX 160W. My initial thought was to use the radio harness since it has power right there, but if I do that, my PC will be subject to my ignition switch; ie, it will turn off/hibernate immediately when i turn my car off instead of using the timer based shutoff in the m2. Is this correct?

My next thought was to wire it directly to my battery as instructed, but that will involve me tearing apart even more of my dash than I already have, and poking thru the firewall. Neither of which greatly appeals to me, but if I gotta, then I gotta.

Finally, I began to think about my cigarette lighter. I have an 03 dodge ram, so it comes with 3 12v ports. One of which I will be removing anyway to install my fancy volume knob. Since this is 12v, could I simply extend those 2 wires to my PC location and use that for power?

Thanks so much for the help, I searched around and saw a little bit of info here and there on the forums, so I figured why not put it all in one thread that people can reference later. That's my excuse and I'm stickin to it!

**v8 scimitar** · 03-07-2006, 05:26 PM

The only way to wire it properly is direct from the battery via a 20A fuse. The radio harness just wont provide enough power and the wire gauge will be too small. The cigarette lighter could work but if anything else gets pluged in at the same time the fuse will blow if it is even actually fused high enough in the first place.

**Dogo** · 03-07-2006, 05:50 PM

I agree with above.
Its good to get the cleanest power source you can - so a fused line to the battery is a good idea. Or at least to where the main power line hits the cabin fusebox.

By the way, your stereo will most likely have both constant power and ignition triggered power lines. So if those wires were actually suitable to be used, you wouldnt have actually had the problem you mentioned.

Give it a good ground to the chassis too, with the paint stripped to the bare metal.

**bmbr** · 03-07-2006, 08:24 PM

Originally Posted by v8 scimitar

The only way to wire it properly is direct from the battery via a 20A fuse. The radio harness just wont provide enough power and the wire gauge will be too small. The cigarette lighter could work but if anything else gets pluged in at the same time the fuse will blow if it is even actually fused high enough in the first place.

Gotcha. Now my followup

and bear in mind that I'm a wiring noob when it comes to cars.. When you say wire to direct via a 20a fuse, what exactly do you mean. is there a good url or thread that explains this? Do you mean to run a wire directly from the battery, and put a fuse inline between it and the power supply?

Sorry to be such a noob, but I am

**necrolyte** · 03-07-2006, 09:22 PM

Its simple, just snag a new wire coming off the Positive of your battery, put a 20A fuse (inside a fuseblock) about 8-12" from the battery, and then run out the other side of the fuseblock inside the cab to your PSU. Keeping the fuse under your hood keeps you safe incase of a short inside the vehicle, the last thing you want is fire

Originally Posted by bmbr

Gotcha. Now my followup

and bear in mind that I'm a wiring noob when it comes to cars.. When you say wire to direct via a 20a fuse, what exactly do you mean. is there a good url or thread that explains this? Do you mean to run a wire directly from the battery, and put a fuse inline between it and the power supply?

Sorry to be such a noob, but I am

**Dogo** · 03-07-2006, 10:30 PM

Something like this inline fuseholder should do the trick
http://www.radioshack.com/product/in...entPage=search

Like he said above, you need to run a piece of wire from the battery to the PSU.
You need to add this fuseholder to that wire , close to the battery is recommended.

And you'll need to buy a fuse to put in the holder too I imagine.

If you drive through water etc you might want to ask if they have a weatherproof fuse holder instead.

**blk02si** · 03-07-2006, 11:33 PM

If you've got 20 amp circuits; hook directly up to the OEM radio power. I did it on my m2-atx and its been working great ever since. But then again when your computer looks like this (below) You might as well hook to OEM power.

I was curios of the same a few months back, and here is my thread about it.
Power Suppy wired to stock radio harness

No noise, Ive also got my amplifier on another dedicated OEM 20 amp circuit. No 'ground loop' problems. Nice clear music. You can always add a 3 way switch to your remote line if you want to control the P.S. Manually.

**bmbr** · 03-08-2006, 05:40 PM

Wow that does look really easy. Thanks for the pictures! When you run a line to your battery, is there typically some sort of gap already in the firewall where the main lines run that i can snake it along next to?

Also, is there an easy way of finding out the amperage of my current circuits?