My lights keep flashing

May be a problem with the flasher relay, easy to change out and inexpensive, if not that then will need the wiring etc checked through

Symptoms sound like the work of an add on immobilizer in the car
Does the car have one ?

If your security light is flashing the alarm is active you need to deactivate it

GoodLuck

Try Re-Activating the Remote System to Lock, Unlock and back to Lock again several times. Does the original problem re-occur? If so there is a problem with the Remote System, and possibly with the Remote itself sticking. Try Lock and Unlock and disconnect the battery. Wait at least 5 to 30-minutes before reconnecting. The remote itself you can take apart and check to see if the depress button is sticking causing the signal to be constantly sent over and over again.

You should not have to reset the key fob after a battery replacement. The signal from the key fob stays the same and is programed to the reciever.
If the key fob needs to be reprogrammed then follow these steps.
1. Have all key fobs with you during programming.
2. Sit in the vehicle with all doors closed.
3. Lock all doors using the Lock/Unlock switch on the door.
4. Insert and withdraw the ignition key 7 to 9 times within 10 seconds (do not turn the key, just insert and withdraw).
5. The 4 way flasher indicator on the dash should flash once or twice.
6. Insert the ignition key and turn it on (key on, engine off).
7. Press any button on one remote and the 4 way flasher indicator on the dash should flash once.
8. If you have more key fobs to program use the Lock/Unlock button on the door to unlock the doors and then lock the doors.
9. Press any button on the next key fob and the 4 way flasher indicator on the dash should flash once.
10. Repeat if you have more key fobs. Only 5 can be programmed.
11. To exit, simply turn of the igniton and remove the ignition key.
12. Unlock the doors using the Lock/Unlock switch on the door and exit the vehicle.
13. Make sure the window is down when testing remotes in case you leave the keys inside.
14. Close all doors and test all remotes that were programmed.

Do not skip any steps or the process will not work.

If the 4 way flasher indicator does not work when inserting the key, you will need to start the process from the begining. If it still does not work the receiver may be your problem.

If the 4 way flasher indicator does not flash when pressing any button on the key fob then the key fob is the problem (dead battery or defective remote)

Suggest that you reset the car's computer... by removing the ground lead from the battery and waiting for 3-4 minutes.
Reattach it and it should clear the problems...
Please let us know! -Jim

you may have had a bad connection at the battery that would cause this kind of problem

The title of you problem mentions the horn but the actual problem mentions the flashers? Which is it? You can turn the 'horn beep' feature on and off by simultaneously holding the lock and unlock buttons down on the remote for about 3 seconds or more. When the horn feature is turned on you will hear the horn, and when it turns off you will only see the lights flash.

This happened to me too...It turned out to be that my door was out of adjustment, which caused the door position sensor to not know whether the door is closed or open. Sometimes my light on the inside of the door would flash (because the car thought that the door was open). Once the alarm did activate, the car would sometimes think that the door had opened, thus causing the alarm to activate. It was cheap to have fixed...I think it was less than $100 at the dealership.

try the key fob battery,if not then test the main battery.