When your Dyson hair dryer is pulsing it's a sign that it is overheating.
The Dyson hair dryer overheating and causing pulsing can be a result of a blockage in airflow or even a dirty filter.
The Dyson hair dryer is made with a built in safety feature which is designed to shut the Dyson hair dryer down when overheating to prevent damage.
Hair lint or other debris can get trapped inside the hair dryer and obstruct the airflow and cause it to overheat which can lead to pulsing or intermittent behavior.
The filter on a Dyson hair dryer is made to trap hair, dust and other debris.
But when the Dyson hair dryer filter is clogged or dirty it restricts the airflow and causes the motor to overheat.
As a result the Dyson hair dryer starts pulsing or has intermittent operation as the Dyson hair dryer shuts down to cool off.