SPDT from siren to horn but stays on?

Ok this is a tough one. I have a Nissan 300zx 1990 2DR coupe. I have a generic/no brand car alarm. This alarm has no output for horn. The only output it has is a positive siren output that is connected to the siren. What im trying to do is to delete the siren and install the horn because the siren is annoying. I took off the siren and hooked up the cars horn directly to the negative and positive from the siren but it required more power.Now I installed (2)  SPDT relay. What i bassically did with the first relay was convert the positive output/trigger from the siren to a negative output with the first relay and then I used the second relay  to convert the negative to a positive ( my car horn is grounded to the metal ) So now im set. Now when I arm my alarm the horn honks once like it should. Very quick nice honk like I like. When I disarm it, it honks twice like it should. Very quick two honks also. Very good so far. BUT. When the alarm is triggered the horn activates itself but stays on. It doesnt even pause just stays on until I disarm it of course. I installed a flasher to cure this problem. After I installed a flasher and arm the alarm and then trigger it the horn now works honks/pauses/honk/pauses like it should.BUT. Now when I arm it or disarm (the only way i know its armed or disarm is when the lights flash) it the honk doesnt trigger like it did without the flasher. So whats the problem? Its a catch-22 I have to pick between silent arm/disarm or honk feature when I arm or disarm and then when trigered the horn will stay on without a pause? So whats the problem.?