No start, no power, no explanation?

I recently aquired a 1992 Ford Taurus from a relative but I'm haivng some pretty confusing technical issues. The car also has an aftermarked alarm system installed, for which I have no instruction manual or any idea how it works.

The battery in the car is brand new, but it apparently has no charge. When I get in the car, there is no electical power at all, the lights in the door don't come on, no cranking when I turnt he key, it's just dead. I checked the connections to the battery, and they are fine. So I got my charger out and started to charge the battery, but as soon as I plugged it in the car alarm went off. So I unplugged the charger and the alarm stopped. I tried several times to no avail. I then opened the drivers door, closed it, locked it, unlocked it, and then tried again to charge it, and this time the alarm didn't go off.

I checked the emter on the charger and it reads that the battery was fully charged. So I left it anyways for about an hour. I came back and when I got in the car I noticed there is a little red light unprofessionally installed onto the dash below the defrost button that was on. I don't know the purpose of this light, but I feel it might be the alarm light. When I put the key in the ignition the alarm went off again, and I fiddled with rhe key and it turned off. I tried to start the car, and the starter tried to crank, but it didn't have enough juice. I still had the charger on at this time. The meter still read a full charge. I then took the charger off and tried again, but this time there was no power again. The dome lights wouldn't work, and nothing happened when I turned the key. I got out and closed the door, and when I did the alarm went off again, only it was extremely quiet and slow, barely audible. I assume it didn't have much electricity.

I next tried to give the car a boost from a running vehicle, and then the car started up and ran fine. I drove it to my house, parked it, and left it running for a while to charge the battery. After about 20 minutes I went out and shut it off and then tried to start it again, but there was once again no power to the car whatsoever, no lights, no cranking, nothing.

I have a feeling the alarm might be shorting out the system or something but I'd like to hear what you guys think about it first. Me and my dad are both completely baffled about this car.

Have you asked the relative how the alarm system works and what problems they were having? Did you check both ends of the battery cables to make sure the ends are clean and secure?

well my thoughts are it is possible something in the alarm is shorted out and causing this. but i think it is more likely it is a fusible link.

Did this issue start immediately after installing the new battery? If so, you probably got a bad battery. I've seen it before. Take the battery out of the car and have it load tested. You can also try charging it out of the car for a complete charge, disconnect the charger, then leave it sit for an hour or so and measure the voltage on the battery. If the voltage is below 12.2 or so, the battery is junk (or your charger isn't working).

If the problems are what caused you to buy the new battery, did you notice a nasty spark when you first connected the cables to the new battery? If so, you have a VERY large current drain. A small spark is normal, but a spark that creates a loud cracking noise when when the last terminal is connected is not normal. I like to install a test light in series with the disconnected negative battery cable to see how bright the light glows before connecting the cable. If the light glows very brightly, there is a significant current draw on the battery. When doing this, make sure all doors are closed, they key is out of the ignition, and the hood light is removed.

Check with your relative to see if they know where the alarm "brain" is located or if they know where the fuses for it are. If not, see if you notice any non-factory wiring under the dash. If you find some, follow it to see if it leads to the alarm module. Disconnect it and see if that make a difference. However, if the alarm were providing enough of a short circuit to drain the battery as quickly as it is, and it was properly installed, the fuses somewhere would blow and disable the alarm.

If you still have a large current draw, try to find a clamp on DC ammeter to monitor the current draw through the positive battery cable. Remove fuses, one at a time, while monitoring the current to find out which circuit is causing the draw.

-Rod

Hey guys thanks for helping. Turns out there were two problems going on.

First of all the battery was defective. I took it down to my shop and the guy tested it. Apparently the battery was working fine whent he car was last used, but that was a while ago. The battery now has the voltage but can't sustain a charge. So I put a new battery in and the alarm went off again and wouldn't shut off until i disconnected the battery, but at least this time if I tried to start the car anyways it turned over and started up fine, just the alarm still continued. So I traced the wire from the siren under the hood to the alarm's main "box" below the dash and disconnected it, and now the car is running fine. The car is not worth stealing anyways so there is no need for an alarm, and even if anyone did take it I wouldn't be losing any sleep.

Thanks for the help guys!