ORIGINAL: 99GrandTouring
Also I wired in a led to the power ok line (orange on my dell) with a 220ohm resitor and the light is actually very dim... the line puts out like 4v and the led is 2v, I don't have any other value resistor, if I wire another 220ohm in parallel would that work to let more current through and make the led brighter?
What color is your LED? Different color LEDs have differing forward voltages, and that will determine the correct resistor value for yours. If you know the forward voltage of yours, here's a handy little LED calculator I use often to calculate the right resistor for any LED.
http://www.rc-cam.com/led_info.htm
If you don't know what your LED's FV is, the color will give you a clue. Most likely, your resistor should be down around 100 ohms to make the LED operate at around 20-25 ma, so putting a second one in parallel should do the trick.
As for your headlamp bulb, a car's electrical system actually operates at about 13.8 volts DC. That's what the alternator produces to run the system and keep the battery fully charged, so if you insert that voltage into your equation, you'll see that a 55 watt bulb should only draw around 3.9 amps, very close to the reading you're getting. I'd chalk the difference up to differences in the manufacture of the bulbs, or maybe an old bulb.
kefa:
You might try connecting that orange sense wire to a different orange wire. I seem to remember that I converted one once that behaved that way. I think I finally decided that there was something about one of the 3.3 volt rails (orange) that was different, and that the sense wire had to be shorted to just the right orange wire to latch the PS on. I now mark any two wires that are connected together in the plastic connectors before I cut them off so I can get them back together correctly afterwards if I need to. You might try that, Andrew can tell us if that's even a possibility or not. I could be completely wrong about it, but it wouldn't hurt to try it.