I just bought a 1998 caravan dodge and it appears when i used the key to unlock doors, it doesnt look like the unlocked switch is working ,when i tried to start the car the alarm set came on and shut down the whole car, i am stranded, the dealer only gave me one key , what do i do?

Shut and lock all the doors. The unlock it with the key or fob. This usually does the job

REPLACE THE REAR DOOR ACTUATOR, THAT IS THE MOTOR THAT UNLOCKS THE DOOR FOR THE HANDLE TO WORK, THE KEY DOESN'T MOVE THE LOCK TO OPEN THE DOOR, REMOVE REAR DOOR PANEL TO ACCESS IT, ROUND HOLE WITH COVER FROM INSIDE CAR WILL ACCESS EMERGENCY KEY WAY WITH SCREWDRIVER CAN OPEN DOOR FROM INSIDE, GOOD LUCK!!

Try using old key in doors to lock and unlock, and reset/disarm anti-theft. Start with drivers door first, then try passenger if that doesn't work.

You either have a bad "arm/disarm" switch or the switch has fallen off from the lock cylinder.

What is happening is the security system is not receiving the disarm signal when you unlock the door with the key. It thinks the car is being stolen so it continues to lock the lock to prevent this.

There arm/disarm switch is clipped onto the door lock cylinders on the front doors and the rear hatch. If it does the same thing with the other doors than there may be an issue with the security system. If the other doors work fine than I would pull the door panel (I assume you are getting this problem with the drivers front door) and inspect the switch.

Here's a pic of what it looks like

If you have any questions let me know.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Try jacking up the front wheels off the ground & then turn steering wheel back & forth while turning ignition key.

Check the fuse for the power door locks.

if your door locks work from the drivers door then the rocker switch on the pass/side needs replaced

pop hood open, lock all doors, disconnect battery for about 3min, reconnect battery & unlock drivers door with key.. this should dissable the alarm. replace battery in fob.

rear latch is going out try unlocking door twice with switch then you have to try the hatch handle twice if that doesnt work there should b an acces hole in bottom of door on inside

sorry not sure the 12v prob will help this swtich works on 5v off 3v unlock 1v lock single wire lock/unlock logic signals
I found wiring diagrams at
http://www.dodge.com/bodybuilder/2004/docs/wd/rswd/tc.pdf
it is 2004 but use the wiring diagrams to test the wires
(most likely to fail where they flex)
because it is using logic gates disconnect the plug at each end of the wire you are testing or the damn thing will find a few diffrent ways to trick you.