My alarm has problems. The battery used to drain after a week of non-driving. I traced that to the car alarm. I disconnected the harness to the alarm box under the dash and the battery stays up now. Of course, now I have no alarm. What could be causing the drain within the alarm? Something the shop hooked up wrong or is this a problem inherent to car alarms?

 

I would imagine that the alarm needs to use some power for it to continue to operate. I would just start the car every couple of days.

 

I had the same problem with my car alarm draining the battery. Most alarms now have built-in relays that can get stuck in the on position. THat causes the power drain. Also, any relays that you had to add to turn on the flashing lights, door locks and starter kill should also be checked. I just installed a new alarm and that fixed my battery drain problem. I hope this helps.