cut out on
phr. v..phr. v.. to suddenly stop working or leave someone when they need you.
phr. v.. to fail or cease functioning abruptly, often in the context of mechanical systems; alternatively, to abandon or desert a person or group unexpectedly.
The engine cut out on us in the middle of the highway.
I can't believe he just cut out on his family when things got difficult.
The radio signal cut out on the rescue team just as they reached the summit, leaving them without a way to call for help.
usually followed by a person or a group who is negatively affected by the sudden failure or departure.
distinguish between the mechanical sense (an engine failing) and the social sense (abandoning someone); both imply a sudden, unexpected loss of support.
The motor cut out us.The motor cut out on us.the preposition 'on' is necessary to show who is affected by the sudden failure.