Horn blows at all times & headlights stay on
 

I turned on the car today and let it idle in the driveway, and after about 15 min of idling I hear the horn go BEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEP... im totally confused. and I turned the headlights on, and when I tried to turn them off, they stayed on, and even if I removed the keys from the ignition the headlights stay on with the button set to "OFF".

I'm assuming that being that both of the problems started at the same time, that both the headlights and the horn are on the same circuit? Has anybody else ever experienced anything like this before?

factory security going haywire?

definitely sounds like security system

If I remember correctly, when I set the factory alarm off once; The lights would flip up, blink and flip back down repeatedly, the hazards would go, and the horn would pulse as well. It then should shut off as soon as a key is inserted (and turned to unlock) into either of the door key cylinders or the trunk hatch key cylinder. I'd try this first if you haven't. Maybe the security system malfunctioned and you can reset it this way.

Incidentally, the alarm only happens for three minutes then the lights all go out and the horn stops blaring. The starter is still immobilized by the Starter Cut Relay, but everything else should be quiet

If the old key in the door trick doesn't work. I'd find the old multimeter and pull out the wiring diagram. There are a couple of relays that might have gone bad (at the same time? I doubt it but they are easy enough to check). It could also be the computer that is in the driver side footwell (referred in Mazda documents as CPU#2) maybe it has failed in some way?

Good luck, finding wiring ghosts are by far not my favorite thing to do with the car. Just be methodical about it and test the proper function of every part of the circuit. If everything outside the control box is working as it should, replace the control box with a good one and you should be in the clear.

I havent tried putting the key in door to try unlocking it yet, I will def give that a shot

I was having the same issue with my headlights, turns out it was a corroded/faulty headlight relay in the front engine bay relay box, not sure about the horn though.

Funny thing, decided to plug in my battery yesterday to start diagnosing the problem, and the horn was not blowing anymore, and the headlights work just fine now? I dont know if the problem was just one of those weird one time things or what, but I cannot get the problem to come back no matter what I do..... I really don't know what to say lol

I had the same issue and the same result you did. So I figured old wiring and let it go. But it seemed disconnecting the battery and reconnecting it solved the issue.

If you still care, arm your alarm with the window open and then open the door from the inside latch instead of the outer one. This should cause the alarm to fire, and recreate your problem. If so, you will know the issue. If you get nothing or a normal alarm sequence, then at least you know if your alarm is working or not.

It's your old girlfriend dicking with you ;)

guys, my security alarm system is going crazy, once i plug in the key into the ignition it goes crazy, lights and horn, and even sometimes when i unlock the door!!! and won't stop till i pull the neg battery plug!

How to disable the alarm system? please tell me guys because it's really annoying and i can't start my car :(

btw, i am not using the OEM key.

Replys are highly appreciate :(
Thanks

im having the same problem did anybody find the problem?

pull the horn relay. it's probably got shorted.