Strange electrical problem

[Datsun240]

So everything has been going well on my car, no changes, when today I noticed that my Viper alarm didnt 'chirp' loudly at all when I turned it off. No matter, I thought, I must have somehow enabled 'quiet' mode or something. I drove to my gf's, and when I went to leave, the alarm wouldnt turn off. Actually, it didnt seem to respond to me at all... just did a 'chirp chirp chirp, siren siren siren' over and over again. Something that I had never heard. Worse yet, seemed very hard to start, like A) there is an electrical short B) something isnt grounded or C) bad battery.

Any ideas? When I finally got it turned on, and turned on my headlights, the alarm shut up. While the engine is running, if i turned OFF my headlights, the siren/chirp thing started. I just had this alarm installed 3 weeks ago and have had zero problems. Any suggestions?

[180fan]

take it back to whoever installed the alarm. one reason i hate alarms is they add a bunch of wires in different locations and it makes it very difficult to diagnose especially online.