How do i disarm cobra 7910 car alarm

The Valet key is not is not a ignition key only men't to open the trunk ect. your dealer can replace and program a new key for you.

The only way to get it working again ,Dealer only . nothing you can do . Need a factory scan tool to program keys . and you can't disarm it either . Software programmed into the computer system .

The key cylinder for the door has a magnetic switch attached to it that sends a disarm signal to the alarm system. If the magnet fell out or wires broke that would explain this incedent.

Ford sold a Ford branded alarm through the parts department. These sometimes were a dealer installed option on new cars. Mine would randomly stop responding to the remote and I would have the same symptoms as you describe. I had it removed and the original equipment factory system still worked. Be warned, if you have the Ford "accessory" alarm, your key fobs (remotes) are different and the method to program them is different from what you will read online. You can tell if you have the system by looking at your key fob. The standard Mustang key fob is a 4 button (lock, unlock, panic, and trunk). The accessory alarm uses a 3 button remote and clicking unlock twice would pop the trunk. I really wish I had a picture of the remote because there are 3 button Ford key fobs for cars without a trunk release although I don't think you should have one on a Mustang. Long story short, if you have the accessory alarm, you can solve your problem by having it removed but you will need new 4 button key fobs to remotely lock/unlock your doors

Nonsense. I just programmed a new remote start fob on my 2011 Santa Fee limited and it worked just great. Follow the steps below and see what happens.
1. Open the drivers side door
2. Turn the Vehicle ignition to the ON position (Do not start the vehicle)
3. Locate the disarm/program button. (look closely, it is located on the wiring harness just inside the lower dash. it could be located just inside the fuse cover.)
4. Press and hold the disarm/programming button for 10 to 15 sewconds, the horm will beep 3 times. Release the disarm/programming button.
5. On the fob, press the Find/Panic button One time and the horn will beep one time.
6. Turn off vehicle ignition. (YOUR DONE)

I don't see where you have any choice but to unlock the doors with your key. If your fobs have good batteries, then the problem is with the alarm system, which can't be accessed until you unlock the doors. I'm not sure what the procedure is on your particular alarm, but with most alarms, you disarm the system by first turning the key in the door lock to the left and then to the right to unlock the door. Turning the key to the left first, disarms the system. Some aftermarket alarms will have a button hidden under the driver side dash that will disarm the alarm.

If it is a Ford Factory Alarm it should have key FOBS (remotes). Just press the unlock button 2 times and that should stop it. Alarm systems no matter what brand always have remotes. If you have remotes pressing the unlock should disarm the system 99 times out of 100. If that doesn't work then either the battery in the remote is dead, or the remote is broken. Hope this helps. Cobra :-)

kept waking neighbours took car to alarm specialist who disarmed it.

Is this a factory installed alarm system? If so, unlocking the driver door with the key will allow the car to start. If not then you will have to remove the aftermarket alarm system to start the car.
If you have a factory alarm system you can get a new FOB (key chain alarm button) from a ford dealer, but it must be programmed using a scanner , before it will work in your vehicle.

ebay. match part number on back of fob. follow instructions in owner manual to program.