reversing alarm output + dei 451

I have a 2002 Dodge Dakota with a Audiovox PRO9644 Alarm, the truck does not have power doors. So I installed 2 two wire door actuators. I purchased the DEI 451m wiring harness to wire it into the alarm. Using a pig tail from a computer power switch and a volt meter I can see the two pins on the alarm module that flips polarity on lock/unlock. I cut the 3 pin connector off the 451 since it didn't fit in my alarm module. Then I took the blue and green and connected them to the flipping polarity pins on the alarm module. I'm using a small 12v alarm battery to test the circuit before I hard wire it. PURPLE / black to +12v on battery. WHITE/ black & BROWN / black to -12v on battery voltmeter on blue & green When I unlock from the keyfob I get +12v, when I lock from the keyfob I get +12v If I reverse the wires on the alarm module, I end up with -12v for lock and -12v for unlock on volt meter. With everything connected if I put my voltmeter on the alarm output, they reverse with lock and unlock, but they are NOT reversing on the other side of the relay. What am I missing?

You need to connect the red from the 451m to +12v, the 451m will then respond to negative (-) pulses from the alarm. You could also do the inverse connect the red to ground, and the 451m will respond to positive (+) pulses from the alarm. While both ways work the former is the defacto standard and the way I would recommend doing it for many reasons.