The BIM is mounted on the wall behind a plastic panel...behind the power cord reel.
Note the mfg. part number and google the manual for that part. It will describe the parameters that must be met for it to close the relay. Time, voltage, etc... if all the parameters are met..,but it's not connecting, it may need to be replaced.
Picture disoriented by irv2 for confusion...
Even without a voltmeter...if you compare voltage readings on the digi-level panel for house and chassis..you can easily tell when they are connected.
Charlie & Ronni
2016 Ventana 4037