I have an Avital Alarm in my car, and I'm wondering if it may be causing some electrical problems with the car. Are some older alarms known for this? [I'm told they are]

 

it is quite possible that it could be doing that especially if it wasn't put in propperly or if something has been stripped out and is touching something.. I would suggest getting a diff. alarm.. I would recommend a viper security system from DEI