[pbuelow]

Can someone suggest a good place to tap to get a strong 12V connection? I'd rather not T off of anything interesting at this point as I'm trying to devise my own type of carputer. I know this has been done to death, but I'm not seeing where these projects get their power from.

Thanks

Pete

 

[zebelkhan]

Any decent carputer will require at least a dedicated 10 amp constant power circuit. I doubt if you are going to find one of those inside the car. I had to run a 14 gage wire from the fuse box next to the battery thru the wiring harness boot behind the brake booster to the inside and use it to power the carputer.

 

[jaak]

Anything that let's you connect a cigarette lighter is going to handle a fair bit of current. There's three in the Murano with provisions for a fourth under the cell phone slot.

Now, an unswitched one, is more likely what you want. It's possible there's an unused fuse position you could use in the existing block...

 

[pbuelow]

Yeah, but I'm not going the decent carputer route. I don't need that kind of headache. I'm going to use a small low power single board computer with an LCD display option so that I can put it pretty much anywhere, and with some power line conversion, I can power it on a 10amp circuit with amps to spare (no hard drive, display on a different circuit, etc). This solution also buys me the ability to put the unit to sleep when the car is off (< 100 mW) so it doesn't have to reboot every time. The point here is to replace my non nav display with a home brew nav display and then whatever else I can cram in there. Thanks for the pointer Jaak, I assume that one of the constant power circuits could be open, which would be perfect.

 

[zebelkhan]

...I assume that one of the constant power circuits could be open, which would be perfect.

Hook up a test lamp to the circuit you plan to use and leave it on to see if it turns off after 30 minutes or so. If so, you will not be able to use it for sleep mode.

 

[jaak]

The constant power circuits are just that... Constant power fused off the battery. It would be interesting to see if the open fuse locations have power connections and what circuit they're on.

 

[pbuelow]

Ahh, all that in good time. I'm just starting to get the details together now. On Sunday, I'll be testing the Radio data line to see what it looks like eletrically, and if it could possibly be a standard RS232 serial line. That would probably also be a good time to put a multi-meter in some of the fuse lines to see what's live when the car is off. Then I get to hunt through the manual to see if any are free. Oh the fun.

 

[jaak]

I picked up my favourite scope from a customer, yesterday, so if I get a chance, I'll do the same and post a screen print.

If I really find the time, I'll hook up the Logic Analyser to all the display connections and capture the start up.

Then I can fire you the file, you download the software and browse through it to your hearts content.

Not only will you see what each signal is doing, but you'll see it relative to all the others.

It takes a while to set up, but it's actually interesting...

 

[MCowher]

I'd like to run a 12V line from the battery/fusebox to underneath my Passenger car seat...Any links that'll help me how to do this? I've never done this before and am clueless...