I have never seen anyone suggest the method you are proposing. Never.

It would be useful to know something about the type of motor, controller, and battery, it's age, and usage pattern, whether it is brand new, suddenly developed this problem out of the clear blue sky, or if, maybe, just maybe, something unusual or slightly different happened to the kit, which WAS working, and afterwards, is NOT working.

There are a large number of possibilities, without additional information, any guess is a shot in the dark. It is quite possible, even likely, that a careful reading of the questions I have posed and a thorough set of answers will narrow down the field considerably.

The suggestion or implementation of ANY diagnostic test or possible solution without that information is sheer foolishness.

The absolute most common cause of ebike problems, including ones that sound very much like yours, is either a loose or broken connection, or a torn, melted, or otherwise damaged wire. Careful visual inspection can be performed without ANY CHANGES at all to the system, no disassembly, little chance for further damage to occur.