Apologies in advance if my terminology is not exact, as I'm a very amateur hobbyist just starting out.
I have a DC servo motor that I bought used, rated at 24V maximum, with variable RPM depending on how many volts I supply to it. The motor works fine when I connect it to a 9V battery, but pulses and drains a connected power supply periodically (every second or so).
I bought a power supply so I could use the motor from an AC outlet (USA - 120V).
This is the power supply: https://www.amazon.com/gp/product/B01B1PRE42
Specifications: Input Voltage: 110V/220V; Output Voltage: 24V DC 2A Output Current: 0~2A Power: 48W Shell Material: Metal case Protection: Shortage Protection. Overload Protection. Over Voltage Protection Safety Compliance: CCC/ FCC / CE Working Temperature: 0~45 degree Storage Temperature: -20~65 degree Ambient Humidity: 0~96% Non-Condensation Package Content : 1 x 24V 2A Switching Power Supply
The power supply has a small green LED above the variable output screw. I tested the output with a multimeter when I connected it with 18/2 lamp wire to my outlet, and I verified (at least I think I did) that it is outputting between 9V minimum and 24V maximum, depending on the screw being fully counterclockwise or clockwise, respectively.
When the motor is connected, it spins for a brief moment (100 milliseconds or so) and the green led on the power supply goes out. Then the green led turns on again (it takes about a second) and the motor again spins and the led goes out, and this cycle continues endlessly.
I have checked that all my positive and negative connections between the power supply and the motor are correct, and the neutral AC to power supply matches as well.
What am I doing wrong?
EDIT: photos of the motor...