Audiovox AX-900 transmitter programming

We installed this remote start / alarm into a Windstar with dual power sliding doors.  The doors operate from a negative pulse so we used channel 4 and channel 5 from the alarm to control the doors.  The problem is that I couldn't find anywhere in any of the manuals what buttons are used to activate channel 5 (or 6 or 7, for that matter).  I tried to program the transmitters; I can get one door to work from the "option" button, but not the other.  There aren't enough buttons for single-button control of the channels so a combination will have to be used for channel 5; however, the unit won't accept programming when more than one button is pressed at the same time.  Anyone know the trick for programming these channels on the AX-900?

Well after digging through all of my manuals I can't seem to find the one for programming transmitters to the brain.  Sorry cheif, might have to call audiovox on that one.Cause I'm So white and nerdy...

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