How do i enable factory alarm system without keychain remote?

To arm content theft alarm.
1. Open the door.
2. Lock the door with the power door lock switch or
the remote keyless entry transmitter. The
SECURITY light should flash.
3. Close all doors. The SECURITY light should go off
after approximately 30 seconds. The alarm is not
armed until the SECURITY light goes off.

If a locked door is opened without the key or the remote keyless entry transmitter, the alarm will go off. The headlamps and parking lamps will flash for two minutes, and the horn will sound for 30 seconds, then will turn off to save the battery power.

Needs Factory programming....

Heidi,
I assume you have lost your original keychain remote. A dealer probably won't be much help since the alarm is aftermarket. Most are.
Your best bet is to take it to a good auto sound shop and tell them your problem. They can find the receiver inside your Trooper, open it up, and determine the make and model of the alarm system, and can order you a new remote(if they don't have one already), and can match the code to your existing system. This should not cost more than $40-$50 and only take 1 or 2 days to order. They can code match it when you pick it up in about 15 minutes. Good luck!

If you have a factory installed alarm the original factory key can activate the alarm by pressing the lock button twice(rapidly). The lock symbol is generally a symbol of a "locked" lock.
If there is no buttons on the car key or it is an aftermarket alarm, a key fab (a little alarm remote control with 2-4 buttons the size of a keychain) is needed to activate/deactivate the alarm.

Are you using the the keychain to lock unlock the vehicle? A low battery in the keychain will send wacky codes to your vehicle alarm system and will not set properly. Try using the key in the door to lock unlock vehicle. IF the alrm does not go off when using the key in the door, then you probably have to change the battery in the key chain. Best guess without being there to look at vheicle.

you will need to buy a new remote and have it and your other keys coded to the car.you CANNOT bypass the alarm.

Unlocking the driver door with the key shuts off the alarm system if it is a factory alarm system.
If the alarm system is aftermarket you may have to remove it . Good luck.

clean battery cables all of them.

factory alarms are passive, if it is working it sets itself when u exit the car. u don't need the remote for the alarm to work if it has a factory system. if u want to test if it is working lock the car with the power lock button and leave the window down, reach inside the car and open the door from the inside handle, the alarm will sound if it is working, to disarm just lock and unlock driver door with the key..

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.