Car Alarms: 98 Camry not starting, starter wire, key cylinder

Question
I just changed the battery in my 98 Camry. Now the alarm goes off when I open the door with the key (it's the car horn)and the car won't start, there is just a rapid clicking noise. (Bought the car used and didn't know it had an alarm until now.)I don't have a keyless entry clicker. I read through your previous answers and have tried the valet toggle, which disabled the horn, but still didn't allow the car to start. Any suggestions? Do I need to get under the dash and cut some wires? If so, which ones?
Thanks! My car has been in my office parking lot for days now and I'm hoping it won't get towed.....

Answer
If you have a valet switch then your system is after market, NOT factory.  Factory alarms use the door's key cylinder to disarm when a remote is not available.  

A 'clicking' noise is normally a sign of a bad starter, not an alarm.  If the alarm was installed properly you would get no noise at all when you try to start it.

To disable the after market alarm, pop down the dash under the steering column and look at the harness coming down from the key switch.  Here is where the system would have been tapped in, removing the fuses to the after market brain should disable the system.  If it was wired in the typical way the starter kill circuit would be wired in a normally closed configuration and the car should start.  If it was wired in a normally open configuration then you would have to find the starter wire (it is a red wire in the 98 Camry) and reconnect it.  

Hope this helps.  Good Luck!