i have a '49 that we upgraded to 12v. i am using a ford ranger 12v wiper motor. to get the range of motion we wanted, we adjusted the length of the arm on the motor. we have a nice range, but the wiper goes too fast even on the slow speed. finally the question: can i use a potentiometer in line with the motor to reduce the speed of the motor? if that works, will i harm the motor running on less than 12v? any other ways to do it? dick r.

 

Remember the past automobilies that had wire wound ceramic coated resistors to change the speed of blower motors. They were located on the right side, engine bay. With modern electronics, you don't see to many pots that would dissipate heat. Use a pot to find the correct resistance for your motor, then replace it with a wire wound resistor. It worked on the blower motor, but the fan was the only resistance. Your wiper motor has more resistance with the wiper assy. Try it, we all need a good,more modern wiper motor. Have a good holiday,chuck

 

yeesh, don't tell me I have THIS to look forward to as well. I am using a 3 speed motor from a mid 70's ford truck. I got it working, and tried to keep the same length when I remade the motor arm ( to use the same park position as the stock vacuum motor).. hadn't thought about actual speed of the wipers.
(so, lets just never use them!!, thats the ticket!)

Sam

 

The resistor should work ok as long as you put it between the switch and the motor. There's gonna be some heat. The switches are the 'Achillies Heel' in the set up when "adjusting" the voltage.

I just broke down and bought a Newport Engineering Wiper Assembly and Delay Wiper Switch to replace my 6 volt electric motor in the 51. It works incredibably well, and it's adjustable as far as arm travel. It's $200 with the delay switch, but how much in time is it worth to you to try and "make something work."

You might want to try installing a delay wiper switch. They are fairly inexpensive at part places. The blades would still move as quickly (they do that because you have changed the lineal/rotational ratio of the motor and arm), but they will do it at a slower rate in the delay mode!

Did that make sense?

J!

 

thanks for the feedback guys. the issue with my set up is that the vacuum was 90 degree sweep and the ranger motor goes in a circle. we didn't use the ranger arm lenth hole at all. we had a shorter arm length working but we went for a little larger sweep. if i get a hold of an ammeter and measure the working current, i could figure the resistance of the motor, that might be a guide to getting the approx resistor i need. i potentiometer i looked at was like 3 watts, seems like it would burn up. thanks again, happy 4th. dick r.