2011 - wipers will not work on high speed

Hello - my father in law has a 2011 Prius -3 - with 135,000 miles on it. He has an interesting issue. The front windshield wipers work on low and medium. When he tries to put them on high, the wipers barely moves. When I drop the stalk back at med or low and it works as if nothing is wrong. I have checked the 30amp fuse and it looks fine. I do not hear any grinding or noise when the wipers are working. I think it could be the motor. However before I go out and purchase the motor, I wanted to make sure there was anything else I could be missing... The dealer wanted 340 for parts and install.. .I know I can do the job myself as I have worked on their other Prius - 2005 with 240,000 miles and counting.

Thank you for all the help,
John

 

Anyway to test????

 

I wouldn't either... Thanks for the info.

 

Thanks for all your help. I did get a motor. I found a new one from a Toyota dealer for 170. So far it seemed pretty easy to complete the job... However a couple of questions...

1: when replacing the motor to the wiper assembly, it was difficult to get the nut tightened to the motor shaft. The 3 bolts that hold the motor to the assembly were easy. I was able to tighten it to where if you were to try to loosen or tighten the arm moves unless you hold it in place.
2: When tightening the 5 bolts and washers down for the wiper assembly to the metal cowl, I hand tightened them and then used the socket wrench to tighten to the point where I couldn't tighten without really pushing the handle.
3: I marked where the wipers where in the home position prior to taking them off as this was a safelight windshield, when I put the pass wiper on I just placed it in position and tightened the two black nuts down. The driver side I did the same. My question after reading some other posts about the wiper arms, I didn't realize about the micro grooves. I also hand tightened and used a socket wrench to tighten.

I wanted to make sure I didn't screw anything up... The wipers worked as well as the missing speed. My concern is either I over tightened something or I am going to some how round out where the arm is mounted. That and the the bolt to where the motor shaft and wiper assembly is connected. I did get a torque wrench, however it did not go low enough for the job.

Thanks again for you help...

 

I will also try to open up the old one today to see what exactly failed.