Hi, I'm having a very frustrating issue with my 98 accord ex v6. I just got it back from the shop a couple days ago where they replaced a bunch of parts of my front right and left suspension and drive systems. The day I got it back after several hours the alarm started going off, I would go out turn it off and an hour or so it later it would go off again. I ended up having to disconnect the battery for the night. The next day I reconnected it and went for a 4 hour drive to my mom's.
I had read that this can happen when the battery is low (it showed no other indications of this however and had no problem starting, also the battery is only about 3 months old) so I though if this was the case the long drive should recharge it and the problem should go away. Well in the middle of the night the alarm started going off again and I ended up taking out the horn and light relays and leaving the car unlocked.
What could be causing this?

Background:
Recently I had had other electrical anomalies, I couldn't get my car out of park without manually overriding which I found out is linked to the brake lights and horn and it turned out that a short on one of the 2 horns was causing the problem. So I simply removed the problematic horn and haven't gotten around to replacing it (the other horn is loud enough).

I don't know if that problem is related to this one but it seems possible.

 

Is this the factory alarm system or an aftermarket alarm system?

 

Yes, please answer this?

If factory, check the hood switch for the alarm. Another common issue and with the work that has been in and around the area something might be out of alignment.