Viper 791 back up battery ?

I have installed a 791 alarm and added a DEI back up battery, the back up battery works, I have the blue wire from the back up battery going to the blue wire in the main harness of the 791 (which is the multi plex zone/trunk trigger wire) and when I activate the alarm, it tells me the trunk is open.  Do I have the back up battery blue wire hooked up to the wrong wire on the 791?

Do you have the red wire of the module going to +12 volts and the gray wire powering the 791? Sounds like the module isnt getting 12 volts on the red wire and sending it into alarm or the module may be bad.

Sounds to me like you need a isolation diode to be placed in series with your blue wire in the circuit. Remember, the battery back up circuits blue wire , is now another input, such as your trunk. It may very well be back feeding into the alarm system. I would install the diode to see if that is the problem, otherwise do a simple test and wire the blue wire to the doors, and see if the 791 does the exact same thing. That will indicate the need for the diode to be placed in series to the blue wire coming from the battery back up circuit. Regards EVIL Teken . . .

Yes it was a diode problem, I am no longer getting the trunk/sensor MSG.  Thanks.