cheap ebay alarm, car won’t start

Sup everyone.  Not a regular on these forums.  I bought a 1995 240sx half a year ago.  A while later I discovered (the bad way) that the car had an alarm installed.  We managed to disable it using a little switch we found by the dead pedal.  Now, months later, I was sitting in a parking lot and tried to start up the car.  It started up fine and suddenly died a second later.  It didn't even stall... it just kind of shut off quietly (which is strange especially for my car).  Now the car will not start.  It doesn't even try to turn over.  Switch doesn't work... can't get the alarm to actually trigger.  The siren makes a strange quiet whirring noise that makes me think it's either broken or in some secondary alarm mode (does this alarm even have one? argh.)

After messing around with it today, it seems the alarm in the car is a pos $10 'auto mate 3' car alarm.  I managed to get it out of the car but the car still does not start up.  I plugged it back in and left the battery disconnected.  We tried jumping the car as an alarm shop I talked to over the phone said if the brain is not in the car it should start.  Needless to say it didn't.  The last thing I can think of (on the alarm side of possible problems anyway) is that the starter interrupt is not letting me start the car.

So I guess I have a couple of questions...  Do you guys think its the starter interrupt/alarm?  Or maybe battery/alternator/starter...?  Something more serious?  Any how-to's or tips for getting the car to run again?  ...Thanks in advance.

Thanks for the quick reply man.  I was going over what I saw today in my head and decided to see if I could find some pictures of the alarm.  Apparently it really IS a cheap ebay alarm... I found the damn thing there. 

Link: http:///.com/dll?ViewItem&item=3074745938&category=14934

I also did some more research.  Looking at the picture of the ebay alarm, I now know which wires go to the siren, LED light and valet switch.  I don't know what the blue/green wire is for (power?).  The wire harness has a white long multi pin plug which goes into the alarm, 2 fuses and a long rectangular black box.  Is this the starter interrupt?  Because if it is, what I *thought* was the starter interrupt (looks like another 4plug relay) might be a alarm-independent kill switch.  The wires coming out of it did not look like any original OEM wires.  I don't know what the damn thing is... it's not part of the auto-mate either?  Any thoughts?  Thanks every1.

No the starter interupt is what the black box or relay if hook up to you need to reconnect the starter wire in your car and take out the starter kill relay the starter wire in your car is a

plug the brain back in and cut the ground...  seems to be a popular choice for alarm uninstalls.  thats what all the brothers bring into my shop...

anyway, find your starter wire and solder it back together.