97 golf won't start

I have a 97 golf that won't start. I has not been started in almost a week. Did drive b/c of the exhaust problem with the catalic converter. when I try to start the alarm goes off & the light in the dash go dim the car does not roll over at all. the neddles in the dash just jump. I got a tune up recently & changed plugs wires, cap & roter. can someone tell me what the problem might be. thx in advance

Low or bad battery or poor connections.