Battery Charger as Power Supply

I just use a car battery.

your battery charger will hum and groan if its an old style
power supplies for students or domestic things usually limited to appox 3 amps, i.e may run it slowly but may just put the supply into short circuit cut out. and you will think the motor is busted when its not.

Wiper motor will pull anything from 7 to 15 amps at initial start up but once turning that comes down considerably, like in 1/2 a second and its at normal running current. i.e a 3 amp supply might work if you could get this far.

yer best bet is to clamp the motor in a vice, stops inertia of the rotor making it rock about on the bench.

connect battery negative to vice
connect the mounting boss of the switch to the vice. (scrap steel with a hole to mount the switch is yer best bet) and wire it up as per standard
that way you can test both speeds and Park

all grounding for the circiit is your vice, which acts as the body of your car, the switch body uses the car body as a ground and so does the motor.
with the motor safe in the vice you are less likely to remove a finger when the thing starts up, that little lever on the output has SOME torque and will, when you are scrabbling to do some other inncououse task, crush your thumb between it and the case..... :)

i think i'm not clumsy or stupid... but i did have a very sore thumb.


Dave