I just received a ProMaster from the company that I work for. It came with an aftermarket alarm already installed.
Factory key fob will only unlock the two front doors, this also includes the inside unlock buttons.
It has become an annoyance because I am in and out of the van constantly throughout the day on every service call, and every time I need to get into the back, I have to fumble for the alarm key fob. I just want the rear doors to unlock like the fronts do when I get out of the van.
I was playing around with it today, using the factory key fob, when I hit the rear door unlock button, it locks the rear doors.
I tore into the dashboard where they hid the alarm control box, I have figured out which wires controls the lock/unlock function of the front doors.
Have also figured what polarity they like to see when being activated. Normally, they are grounded, and then when activated by the key fob or interior buttons, either the lock or unlock wires are energized with 12v.
There is one more wire, a red/black one, that this alarm is tied into using a relay. I am suspecting this has something to do with the rear doors. I need to make some jumpers to bypass the wires they cut to install this alarm, essentially returning it back to stock and then test this wire to see what polarity it receives while activating the factory system.
All these wires are located in the fuse block under the panel to the lower left of the steering wheel. There is a large plug at the bottom left, this is where they tied into for the locks.
I found this site looking for a wiring diagram (and to figure out if I can add rear speakers). I have yet been able to locate one.