I have a 1996 ford Explorer with single button on key fob and it has stopped working can I Bypass the alarm/immobilser and take it out of the system alltoghether

If you just want the car to crank and run try locking and unlocking the driver door with the key then switch it on for 2 mins and then try cranking it that works sometimes. when you dont have a remote.

fob doesnt control immobilizer key has security set up --fob is designed to open and lock doors and reset alarm ---and no bypass to immobilizer

There is no reset button on an OEM system. Instead of trying to disarm the anti-theft, arm it, then start the car. Press the "Lock" button on the key fob, put the key in the ignition and see if that works.

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

Unfortunately there is no way to bypass the immobilizer feature, the key you are using is probably not matched to the system, if all keys are lost you should contact the Toyota dealer there is a way to program your existing key or a new key to the system, doing this requires a diagnostic scantool.

How to disconnect anti theft system in may ford explorer 1996 v6

Yes, Fords have PATS system, which is what controlls your keyless entry. It is the computer for your key fobs and keyless entry. You might have tripped itby accident, and your only solution is to take it to a dealership or someone who has Fords reprogrammimg computer to have it reflashed.

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.