I have a 98 ford Taurus and the car alarm keeps going of for no apparent reason. I don‘t think pulling the fuse on the horn would work because the lights flash to.
Could be the sensor is to sensitive. I know this is sounds weird.but I know that sometimes theives will set off the alarm several times, which in turn forces owners to turn off the alarm so as not to bother neighborswhich then leaves the car possibly unlocked.
Is it the factory alarm or aftermarket? Factory alarms don't have vibration sensitivity, they'll only go off if a door is opened or if the alarm isn't working correctly. So, if it's a factory alarm that's going off then something's wrong. This is often caused by your battery being very low and not being able to provide the alarm with enough power to function properly. If you've got an aftermarket alarm it's probably that the vibration sensitivity is set too high. It's very easy to change, just find the brain (usually under the dash on the driver's side) and look for the dial on the side of it. Turn it up so it goes off when a fly lands on it or down so it doesn't even go off if it gets hit by a semi.
Your alarm is being triggered by the Auxiliary power sounder due to the built in battery failing causing the alarm unit to think that the car is being tampered with. The power sounder unit is located behind the drivers side wheel arch splash guard on the left it is held to the car in a metal housing which is secured by 3 bolts. You can purchase a new power sounder unit or disconnect the unit and tape the connection lead to prevent water ingress if you don't want to pay ?70 for a new unit. Before disconnecting switch on ignition switch off and remove the battery negative lead withing 20 seconds or the alarm will sound. If you choose to remove the power sounder you will still have the default alarm via the main horn if the vehicle is broken into and is sensed by the interior sensors. This can be tested with the drivers side window down then lock the doors there is a indicator lamp in the hazard switch which will be steady on for 1 minute then flashes intermittently. If it flashes fast don't worry after a minute it will slow to tell you the alarm is activated. Once it is flashing steady reach inside the open window alarm will now sound, Unlock car to disable alarm.
