I'm troubleshooting the DC motor for a 14W Lucas windshield wiper (from a 1970 Land Rover). I tried a number of things with no luck so I'd like to see if it's a problem with one of the brushes that is only partially touching the commutator. Before I buy new brushes (which are hard to find), I'd like to find a way to test whether that's actually the problem.
So I've tried bypassing the brushes by touching the wires from a power source directly to the commutator. Nothing happened. But I'm not sure if that should have worked. I don't have a good motor to compare. Can I bypass the brushes this way?