super noob asks: m2-atx help (soldering, fuses, wire gauges)

**dvsdimsum** · 10-24-2008, 06:09 PM

Hi all. A bit of a

lurker

here, and I've finally mustered up the courage to jump into this hobby. I've recently purchased most of the basic hardware I think I'll be needing. This includes the monitor (Lilliput 701), the computer (intel's D945gclf2), and the dc-dc power supply (m2-atx). There's also the usual USB peripherals (GPS, bluetooth, etc..), but that's more standard of computer equipment, and not-so-much carputering, so I'll leave it out for now unless someone finds it relevant.

Here's where I hope you guys can come in:

1) While I've tinkered with computers and electronics before, I've never had to do any soldering. I've spotted THIS at my local Radioshack, and was wondering if it'd be sufficient for a beginner like me on such an ambitious project? Obviously keeping the cost low is important, but I'd like to hear if the mp3 community has some sort of consensus as to a good beginner's soldering iron/gun/kit. This will be doing all the wiring from the m2-atx to the car, so let's not watch me set a car on fire, yes?

2) I've done some reading on the wiring for the m2-atx. I understand that I'll need to wire some stuff from the PSU to the battery, and also that I'll want to include an in-line fuse. I'm only familiar with automotive "tube"-looking fuses, but I've also googled some "blade"-types that seem to be flat. Anyone have a good reference to learn about this? Especially nice would a recommendation as to the amps I should use to protect the PSU. I've seen comments ranging from 10A to 20A, but that range is both above and below the 15A on the m2, which doesn't seem to make sense... Which will better protect the m2?

3) These forums have lots of great MSPainter's and PSer's that gave great diagrams. Once I get under the hood and start poking around, I'm sure I can figure out a lot more. However, I'm not sure of a few things: the m2's wire gauge (I've seen comments ranging from 16 to 18, and recommendations to use 10-18 gauge for other stuff), how you guys went about connecting it to the battery itself (banana clamps? those loopy-things?) and how important is it to ground the PC and its components (I've seen some in the trunk on just wooden boards, others wired straight to the car's chassis).

Whew, that's a mouthful. Anyways, you guys rock, and hopefully I'll be able to post something in the "show off your project" soon enough!

Thanks for such a great source of information!

**DarquePervert** · 10-24-2008, 06:41 PM

1) Yes, that kit would be fine. Hell, it's probably better than the one I use.

2) A fuse is a fuse. They all serve the same function. The blade-style fuses are what is commonly used in automotive applications anymore.
When you put a fuse on a power line, that fuse is to protect the wire, not the device connected to it. Since the M2ATX has a 15A fuse, you'd want one rated slightly higher. 20A would work nicely.

3) 12awg would work for a short run, but I'd recommend 10awg to be 100% safe.
You need to ground the PSU properly. The PC itself should be grounded back to the PSU, so there should be no need to ground the PC itself unless you're having some unusual problems.

**dvsdimsum** · 10-25-2008, 04:17 PM

Thanks for the quick reply!

One last thing now, someone tell me if you see any potential red flags in my install.

1) Looking to wire the lilliput to a 12v molex (via a chopped cigarette power plug adapter) on the m2-atx. As far as I can tell from other threads, it should wire up just fine and I'll have no issues with crank or power fluctuations, correct?

2) I'll be attempting to mount the D945GCLF2 and m2-atx in a glove box. Disregarding the cooling issues at the moment, the motherboard, if mounted inside on standard PC standoffs and grounded to the m2-atx via the atx connecter, is fine and only the m2-atx needs to be grounded to the chassis of the car?

3) Since I'm keeping the headunit (keeps cost down, less complicated than getting an amp and other equipment, etc..), i don't think i'll be using a distribution block or terminal strip. i'm thinking of using a DPDT switch to enable alwaysON/alwaysOFF/IGN with the m2-atx. Simply, motherboard + USB + screen all power off the m2-atx, the m2-atx is wired to battery and ignition, and no other wiring is needed. correct?

i'm picking up a solder after the weekend, and the fear/excitement of dismantling the dash has me restless!

**DarquePervert** · 10-26-2008, 06:53 AM

1) None whatsoever. The M2 handles the voltage regulation, and the lilliput would be behind the M2.

2) Correct.

3) Correct, but I don't understand the use of your switch.
If you put the switch on the ign line, it acts as a valet switch and functions thusly:
Ignition off + Switch off = PC Off
Ignition on + Switch off = PC Off (no current on ign line to trigger bootup)
Ignition off + switch on = PC Off
Ignition on + Switch on = PC On (this is the only state where current goes to the ign line, triggering bootup)
You can also use the switch to initiate shutdown or startup of the PC.

Your description sounds like something else, but I could be misinterpreting. It is early and I haven't had coffee yet.

**dvsdimsum** · 10-27-2008, 02:10 PM

good catch. i was looking at this post, and misread. it looks like i need a SPDT, not a DPDT for the "valet" switch. whew, saved me a return to the store. thanks!

**skuller** · 10-29-2008, 12:52 AM

Originally Posted by dvsdimsum

1) While I've tinkered with computers and electronics before, I've never had to do any soldering. I've spotted THIS at my local Radioshack, and was wondering if it'd be sufficient for a beginner like me on such an ambitious project? Obviously keeping the cost low is important, but I'd like to hear if the mp3 community has some sort of consensus as to a good beginner's soldering iron/gun/kit. This will be doing all the wiring from the m2-atx to the car, so let's not watch me set a car on fire, yes?

The solder gun would work perfectly fine for your project now.
If you're thinking into doing some pcb work with it, forget it.