Let’s talk about scooters and their motors!
There’s three major components to the motor assembly in a scooter.
One is the motor itself, which is always 24 volts (nominal voltage). It can be a little bit higher or lower but it is basically 24 volts.
Two, the transaxle gear. This passively drives one end of the shaft while the motor actively drives the other end of the shaft. The result is that a working motor assembly should, when you rotate one of the wheels, the other should rotate in the opposite direction without too much friction. This is a good way to test if your motor assembly has damage or needs regreasing.
The third component of a motor assembly is the braking solenoid. There’s two parts to a braking solenoid, one the manual release, which is nothing but a hex bolt which the motor moves, that is put into a locking position when an octagonal piece of metal snaps over it. Scooter users will be familiar with this by the handles they see protruding from the end of the motor. The second part is an active solenoid which works an an electrical automatic braking system. This automatic braking system you can hear clicking whenever the throttle for a scooter is released to its normal base position.
Some brake assemblies also have a micro switch that is either pressed or depressed when the manual brake is applied. This isn’t commonly used in motor controllers but is meant as a computer override.
Most mobility scooters only have 4 wires from the motor assembly to the motor controller.
Black wire, -24 volts.
Red wire, +24 volts.
Two other much finer gauge wires, often white, for the solenoid, where polarity is not relevant.
That’s the basics of a motor assembly.
For anyone wanting to buy, repair, or replace a motor assembly, it’s extremely important to know several things. If at all possible, get the complete motor assembly with the wheels and mounting brackets completely intact. This is hard to find and can be very expensive. If you buy new motor assembly, they almost never include the wheels. Due to the competitive nature of capitalism, manufacturers have varied the ways of mounting motor assemblies that are the exact same size and have the exact same purpose. This includes altering the ways that wheels are mounted onto the axles by changing the indentations of the axles themselves, the screws, the threadings, everything.
Powerchairs are a different story entirely…