Wiper bench test…on car

Ah well. Didn’t work. New project, then.
However I did do a voltage test at the firewall connector. The main feed wires (Brown, red) to the wiper motor show battery voltage With switch turned on. I cleaned everything at the connector, reconnected and then checked voltage again at the two power wires. Somewhat amazed to find just 3.8 volts showing.
I can’t belivee that such a voltage drop could be possible given that the connections are clean and feel tight at the connector.