Horn beeps as if in an alarm mode

So I talked to someone who suggested my battery might be dead and that I try charging it, but as "Bullmtnbiker" mentions, the horn blasted as soon as I connected the negative terminal of the battery to charge. Finally, I just tried connecting it and running into the vehicle to start it, and that stopped the horn blasts immediately and it started and ran fine. I just hooked up to a trickle charge overnight to get the wounded battery back in shape.

the horn beeping at random is indicating a fault in the alarm system. alarms have their own battery which is balanced by the car battery and any unbalance ( corroded connections -bad earth, low charged battery in alarm, loose battery connections ) will cause the horn to sound --same as too sensitive a setting for the alarm or a intermittent power to the alarm

Sounds like you need to reset your alarm kill switch, which should be located near the driverside kick panels. GL.

what yesar and model please?

Disconnecting the car battery will reset the alarm system. When you first connect the car battery, the alarm will sound briefly, then stop. You will have to retrain the alarm system to recognize your remotes. The procedure for that varies from one year model to the other. On my 1998 you do it by putting the key in the door lock and holding it full counterclockwise until you hear a brief beep from the alarm horn. Then press a button on your remote and the system will learn to recognize that remote.

As long as you have a key,original or copy, when you hook up the battery use the key in the door and turn it to the unlock position, that should de-activate the alarm. either front door should work.

Have you checked your Fuses sometimes if one blows it could cause the car not to start depending on the fuse.

try honking the horn normally with horn button <key must be on> if horn works it is in the programing for comfort and convieniance system if no honk it's just the horn or wiring to horn.

PURPOSE OF ALARM SYSTEM IS SO THAT WILL WARN IF BEING STOLEN ALSO CAUSES IGNITION SYSTEM TO BE DISABLED BY SHUTTING OFF FUEL PUMP POWER SUPPLY WILL HAVE TO FIX ALARM SO VEHICLE WILL START

You have a broken rotating contact under the steering wheel, it is a ribbon that looks like a clock spring, it is called the air bag clock spring contact, anyway replace it and your problem will be fixed, be careful to disarm the airbag before you pull the steering wheel, disconnect the battery for 1 hour and then disconnect the airbag control module before starting any repair.