Alarm HELP!! for 99 Galant

I had an alarm installed on my 99 Mitsubishi Galant about 2 years ago.  Now it won't alarm or disarm.  If I use the remote it will not do anything, it makes a noise like it wants to work.  The lights don't flash and now I can't even lock the doors without the key in the ignition.  Is this problem because of the car alarm?  This alarm is useless now, but I want to know if it is something simple that can be fixed.  I know its getting some type of power because it tries to work.  Every now and then it will try to chirp but then it stops.  And to make matters worse I tried to take it back to the installer and they are not even in business anymore!!!  Great. Any type of help will work.  Thank youDawn C.

What kind of alarm? When you say makes a noise like it wants to work can you give more detail? You may have a power/ground problem. How much do you knwo about alarms, if some going to have to find the brain and see the power/ground wires.