I bought a broken remote control car that I am re-architecting and trying to get to work. The steering for the car is done by a small DC motor. Although the motor is tiny, it runs off the 9.6 Volt battery that powers the rear wheels as well.
The motor worked fine for a couple of months, but now does not turn on at all. It goes through a gear box that actually does the steering. The design of the steering is a little strange. The motor's either full on right or left, or it's off in the center.
So to turn right, for example, the motor turns until it is stopped by the mechanical resistance of the wheel bumping against a block, and the motor then holds that position until the current is turned off. A spring then pulls the wheels back to center. So I would guess that the motor is stalled the whole time it is holding the wheels in a turned position, and pulling the stall current for the motor.
My guess is that the motor burned out because of pulling stall current for too long a time, but how could I check that? If I hook it up to a power supply and check for voltage across the two motor terminals, I get nothing. If I check for continuity across the two motor terminals when no power is being applied, it is an open circuit. That's all I could think of to test.
A visual check reveals nothing unusual. The two motor terminals are attached to a small PCB board that seems to have a few surface mount resistors on it. I have not taken the motor apart.
I cannot see any writing on the motor. I can take a picture of it if that would help.
Any suggestions would be appreciated.