03 durango autopage unlock problem

I recently bought a 2003 Dodge Durango a few months ago. It has a Autopage C3-RS-730 LCD start/alarm system. Everything functioned and I had not messed with anything to do with that, then without reason one night it disarmed but did not unlock the doors. The system will arm/lock and unarm but will no longer unlock. I don't know where to start looking to find a problem. Thanks in advance.

Do you know where the alarm brain is located?

What happens when you try to unlock from either front door with the factory key or keyless entry if there is one on the key fob, it could be either a vehicle problem, lock output problem from the Autopage, a failed relay or a blown, or de-soldered resistor.

I think the brain is behind the kick panel or under the dash below the steering column.

It unlocks with the key, I only have the autopage fob.  When I push the disarm/unlock it only disarms now. It just stopped unlocking randomly one night.

You will need a DMM and access to the alarm brain. Two wires possibly green and blue (Check with Autopage) green will output NEG on lock, blue neg on unlock, first test the blue. They should feed a pair of relays with resistors on the outputs,. again make sure the relays work by testing the outputs, then again after the resistor. Values should be under vehicle wiring for that year and model as listed here in the vehicle wiring section. After the resistors those wires should join together with the vehicle's unlock wire again listed here.