A car alarm without a remote can be disarmed by opening the door with the conventional key and then locating the valet switch. Upon entering, the alarm sounds. Locate the switch immediately, insert the key into the ignition cylinder, turn it to the on position and gently hit the valet switch once.
This should reset the alarm, stop its blaring sound and enable the car to start. If tapping the switch once does not work, turn off the ignition and try the process again several times. The alarm system may have been programmed to require up to five taps on the valet switch.
Most people find themselves in this situation when they have lost or damaged the remote to their cars. In this case, it is always important to know where the valet switch of the alarm system is located.
Sometimes the alarm may not be disarmed even when the remote is pressed. This might be due to low batteries. When the remote has to be pressed several times to open or lock doors, it is a sign that the batteries need to be replaced. Read the manual to determine what needs to be done. Different alarms are programmed differently, so what works on one car might be ineffective on another.