When I went to an electric motor, the arms and blades flopped around. I studied the situation under the dash and after a while, concluded the one arm was too short. I got brave (or was it stupidity) and cut the arm and put in an adjustable piece with slotted holes.

It worked but I still wouldn't advise anyone to do this. Note I could still adjust the arm to the previous total length.

Attached Images
WiperArm.jpg (21.06 KB, 22 downloads)

1948 3/4-Ton 5-Window Flatbed Chevrolet [sandeace.com]

31 Years of Daily Driving. With a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.