Wipers won't park or intermittent mode with engine running. Works fine in ACC any Idea's

[bassoneman]

I have a 2015 Thor Hurricane 34j.. This is driving me bonkers.. Ford replaced to wiper module last year. Didn't fix it. I had replaced the motor and the wiper switch steering column year before that. I have metered out the ground seem fine with a meter.. Any idea's . I wonder if I cut the ground wire to the wiper motor and go directly to the neg battery terminal If that would have a good effect vs bad. I don't have a schematic so I don't know if the ground is coming out of the control module.. When I mean wont park I mean they won't shut off and park. I have to turn the engine off and put it in ACC so they will shut off.. Not a lot of fun while going down the highway and it stops raining. High, Low, Washer work fine..

 

[Henry J Fate]

What changes from the ignition ON position to the ACC position?

The only thing I can think of is higher voltage in the ON position from the engine alternator. Probably a couple of volts. Possibly more depending on the state of charge and the battery capacity.

When you have a chance, check the voltage at the battery terminals in the morning before starting. Then take a second reading after the vehicle is warmed up and still running.

For grounding, bring a jumper from the neg battery terminal and connect it to the existing ground to see if that changes anything.

 

[bassoneman]

There is a ground connection to the chassis some what near the wiper motor however I am not sure if that is where the wiper motor ground is connected. I removed that ground wire and sanded the metal bare to have a good connection. I ran a wire from there to the neg battery no effect. I ran a wire to a screw where a ground wire comes out of the on the casing of the wiper motor still no effect although not sure if I had a great connection, I just barely got my alligator clip clipped on it.. I will check the voltage at the battery in the AM like you suggested. I tried to find the same connector online. I even thought of creating a switching system test that bypasses the the wiper control module and see if it will park. I may be able to clip on to the wiper wire connector with single wire connectors..