I have a dell 600m hooked up to a carnetix, but the laptop won't turn on when i turn on my car. I can turn on the laptop by pressing the power button though after the carnetix is loaded even without the battery in.
I know the ignition isn't the problem since i am just using a 12v source as the ignition.
Any idea what's going on?
Ah, well in short you need to open the laptop solder wires onto the switch and bring them outside the case. There wires get connected to the startup-shutdown controller.
For more detailed you best get searching as there are loads of posts on this subject.
I don't know where you got that little piece of information, but it is incorrect. The Carnetix has to simulate a press of the power button in order to initiate bootup.
If you don't feel like cracking open the laptop, I'd get a port replicator and hack that (or maybe the monitor stand to boot)
I have an inspiron 8600, which IIRC, uses the same dock/port stuff (double check). I paid I think around $45 for the port replicator (D/Port APR) and a monitor stand on ebay.
They are cheap and tons of them on ebay. I got the monitor stand for two reasons. One, two protect the laptop from crap rolling around my trunk, and two, it was so easy to remove the little power button board and short it out (on the inspiron 8600, this makes it boot when power is applied, you'd want to use the wires provided to pulse it, I used power management to shut it down when it loses "AC").
Here's a pic of the monitor stand and dock.
Just keep poking at it with a screwdriver until it turns on, then you've found the correct 2 pins to wire to.