DEI alarm will not respond after remote start on

1996 Dodge Ram 4x4, I have an older early 2000's APS not sure what model Prestige/Audiovox Alarm. It has the third channel, negative out pulse that triggers a 561T R add on remote start module with the third button on the remote. The batteries have been out w engine rebuild and my Delima after fooling with this for two days is: The Alarm will arm and lock doors, and the remote start will crank truck up after pressing the third channel button., BUT after this when the truck cranks, the Alarm is no longer responsive and and I can no longer lock/unlock the doors to get in, nor shut the remote start off with the remote. This has got me stumped why the APS Alarm PCU ( Alarm Brain ) just becomes unresponsive after the remote start is engaged.. I need to get this corrected..   Thanks for any ideas.

The alarm won't respond with the ignition turned ON. This is normal. If the alarm has a shock sensor you should consider changing the system out to an all in one remote starter/alarm unit. Otherwise the engine starting will trigger the shock sensor. If you remove the shock sensor, you can use a relay activated by the status output/negative out when running circuit from the remote starter to open the ignition feed to the alarm. Cut the alarm's ignition wire and connect the cut ends to terminals 87a and 30 of a relay. Terminals 85 to remote starter's status output/negative out when running and terminal 86 to fused battery power.sparky

you are probably right. it is probably time to upgrade to an all in one system anyway. Thanks

The 561t has a yellow wire that is for the ignition connection to the security system. When the RS is active, the yellow wire is not energized, so the alarm doesn't know the ignition is on. Connect your alarm's ignition input to the 561t's yellow wire. On DEI alarms, this wire is also yellow. I don't think this is your problem. The alarm should trigger if it sees the ignition come on when it is armed.