Need Feedback On Wiring Thoughts

**jpinkerton** · 04-23-2009, 03:08 PM

Okay, I'm moving along on my Car PC - and I'm confident I could do the wiring myself - just so long as I know what I'm doing is the right way. I'm new to this, I've done household wiring, replaced the factory stereo, simple stuff.

I appreciate any and all feedback/thoughts on this, and by all means if I'm under the wrong impression or have suggested something that is just down right stupid, PLEASE tell me

Okay, my planned setup is:

Zotac 630i Mini-ITX Motherboard
Intel Celeron 430
320GB WD SATA Laptop Hard Drive
2GB Kingston Low Profile DDR2 RAM
M4-ATX Power Supply
Lilliput 7" EBY701 LCD
Garmin GPS15 Module (Down the road)
Visteon HDZ300 HD Radio (Down the road)
SATA Slot Load DVD Drive (Down the road)

I added everything up and I'll be pulling 50W/40Amps - which according to the chart means I'll need to use 10 guage wire for a 10' run. I'm thinking I'll bump that to 8 guage wire for the 10' run just to be on the safe side, and in case I add any devices down the road I wouldn't have to necessarily rerun this wire. I'll need to put a 50AMP fuse within about a foot of the battery for the 8 gauge wire.

Now, I'm thinking of replacing the terminals that are on my battery currently with the positive and negative Metra ones from the MP3.com Store. I have an open accessory plug in my fuse box.

Tonight I'm going to look for an opening in my firewall that leads into the engine area of my car. Hopefully I can find one, else I have to find a place and drill/grommet the hole - which I would not be particularly fond of.

I'm thinking of shielding the cables when they're done with some sort of snake skin type wrap just to keep all the cables I'm running together, pretty, and secure. This wouldn't necessarily be needed, but would be nice.

I'd like to run the positive/negative leads into a distribution block. This one from the MP3.com store looks decent. This would let me run wires then from the distribution into the LCD, computer, and any other devices.

Now, as an aside - I believe I would need a ground distribution block. I took a quick glance through the store but I didn't see one, any advice on that part as well?

So then the M4-ATX goes into the distro, the LCD goes into the distro, and any other devices as needed (up to 4) into the distros.

I thought I read somewhere that I need a resistor, but I can't seem to find that again.

I appreciate any and all feedback on this!

**jpinkerton** · 04-23-2009, 04:29 PM

I was going back through all my bookmarks and I believe I was wrong, not a resistor but a relay. One between the power supply, LCD screen, and down the road - amp?

**RadRacer** · 04-23-2009, 09:17 PM

The distrobution block you picked out is for 4AWG in to 2x 8AWG out. You'll want a smaller one for 8AWG, or just don't even worry about it; just run the main power to your PSU. You don't need nearly that big of a power wire for the LCD. Do you have post (top) mount battery terminals, or the side-mount screw in type? If it's side mount, those Metra ones won't work. You can ground each item individually as needed, but this sometimes leads to a ground loop; if you "have" to have a ground distro box; just use the same kind from the positive, but in reverse. As for relays, they're used when high amperage is required, but the switch (or device activating it) can't support it; I don't see anything really that you'll need a relay for, but I could be wrong.

**jpinkerton** · 04-23-2009, 09:32 PM

Thanks for the catch on the distro box, I reversed the numbers in my head.

The posts on my battery are on top, not side mounted.
If anyone else can comment on the relays - that'd be great.

Also I looked tonight and I don't think I'll even need to go through the firewall, there's enough of a gap in my body to bring the wire inside, and I found where I'll mount the fuse just before bringing the wire into the cabin.

**jpinkerton** · 04-24-2009, 07:53 PM

I snapped a picture of my battery today - it's gross, but I just replaced it earlier this winter. 1000 Amps/800 Cold Cranking Amps

**RadRacer** · 04-24-2009, 11:25 PM

Fuse should be within 1ft of the battery

**jpinkerton** · 04-25-2009, 02:12 PM

Rad do you by chance know whether I'd need to put a relay between the LCD and the power supply? I'd like to connect the M4 power supply into the LCD to power it.

Here's a picture of what I'm thinking overall. What am I missing?

**RadRacer** · 04-25-2009, 09:12 PM

shouldn't need a relay for the liliput. You only need the 50A fuse on the positive line.

**jpinkerton** · 04-25-2009, 11:46 PM

Awesome, thanks RadRacer for your help with this - here's my revised one.

I'm a very visual kinda guy. Seeing it laid out like this helps.

**jpinkerton** · 04-27-2009, 11:28 AM

I did some modification to get the Thin Client to fit behind my dash. I was thinking where the Cig Lighter use to be would be a perfect place for a rocker switch. I was thinking of just a simple On/Off style switch to prevent the computer from starting up when the ignition is started. This way if it is sub zero (happens in Iowa) I can let the parts warm up before starting the computer.

So here is the revised plan, am I on the right track with the ignition line here? I've read and looked over other samples and I think I have it right but sure appreciate any/all feedback.