Anyone know how NPN transistors work?

[itjstagame]

Ok, there's a lot of smart electronics people on here I've notice. I only have a rudimentary knowledge and I'm having an issue.

The Festiva I got, the first day I drove it I noticed that the headlights are wired directly and ignore key input and do not buzz or anything, and thought "Man I'm going to forget about these lights sometime, I should wire this to go off with key out".

Then 3 days later I forgot about the lights and killed the battery and got stranded on the side of the road and lots of fun stuff.

So I ripped apart the dash, cursing my laziness, glad I'm finally doing this and find out that the parking lights and headlights are wired through the relay already to main power and the headlight switch is just grounding them. Not as simple as just supplying a different power source to the relay as I had hoped.

Then I thought, hey, I know how transistors work, if I wire the ground wire coming from the switch to the collector, the emiter to ground and the base to accessory power, that should work great!

So I wired it up everyway possible with this transistor. With the ground wire from switch cut the headlights don't come on. WIth leads hooked to emitter and collector or vice-versa, either one, I can diode test and connection test and verify there's no connection between the leads, but when I turn the headlight switch there's a connection between the emitter and collector. This is with NOTHING hooked to the base. So is there a certain voltage or current that just 'jumps' the base of a transistor? Everything I've read says 'no' and that anything less than 15V will work fine as expected.

Also am I going about this the wrong way anyway? Even if it works as I expect and I need to put power at the base to complete the NPN connection, removing power from the base, will that 'turn off' the NPN connection? I've seen a lot of applications where once transistors are 'switched' they stay that way until main power is removed.

Any thoughts on how I can accomplish my goal? I guess when in doubt I can just put a buzzer inline connected to accessory power too.