where is the mux port on a 5901

i run into the same issue. Here is the diagram of my viper 5901 brain unit: I bought 2 aftermarket two-stage microwave sensors (4 pin connectors) and the plug doesn't fit into Viper MUX port.   But fits perfectly into D2D module port (on the right).   So my question is, maybe there is a mistake on that diagram? Can somebody confirm which is the correct MUX port?    and also what is its pinout? i mean: +12V ground 1 input 2 input or maybe there is only one input? instruction manual says ZONE4 =sensor 2 MUX port.     and how all this works?   is power supply constant or only when armed?   Thanks.

gee i need to update this, and my other posts for that matter. This is the correct information: The four pin MUX port from above diagram is correct (bettween neutral safety and door lock connectors. The pinout is: (from the left, neutral safety..) 1. input 2. input 3. ground 4. +12 constant When we supply gnd signals (eg from external microwave sensor) to either input 1 or 2 it results in warn away chirps, and LC3 remote displays 'hammer' icon and reports: Sensor 2 I don't know whether those two inputs are internally diode isolated, and also they seem to work exactly the same, maybe somebody else knows more, please share the info then.