I have been having trouble with my intermittent wiper feature and the windshield washer feature and parking of the wipers. For the last two years--since I had the truck. It is a 92 F150 with the intermittent wiper option.

My wipers wouldnt usually park --hardly ever.If I turned off the wipers and the wipers arms were vertical at the time--they would stay vertical when the wiper motor was turned off. If I used the washers--the wipers would continue to wipe--and wouldnt stop until the truck was turned off. And the intermittent wiper function wouldnt work--the wipers would work at normal speed and high speed--but wouldnt intermit the wiper action--because they wouldnt park momentarily.

I have done searches on this site and these problems are common. I read about Wiper Control Module issues and MF switch issues and wiper motor issue failures. These problems can happen and can cause these problems. But I would guess that there have been many wiper motors replaced unnecessarily to correct these problems

I found a possible no cost solution.

Pull off the top black connector on the wiper motor assembly. It will have a dark green lead and a black/orange tracer lead and a black lead. These leads are for the park function of the wiper motor. Take a digital tester and check for intermittent continuity between the top and middle terminals on the park motor assembly--the round housing on the driver's side of the wiper motor assembly. Check for continuity when the wiper is still moving--wiper on and key on. You should see continuty--for top 9/10s of the wiper stroke and the continuity should disappear during the last 1/10 of the stroke of the wiper--at the bottom of the windshield--the park area of the wipers.

If you dont see the circuit go open--or dont see continuity--remove the circular park switch housing cover--at least four plastlc clips--and bend the two floating contacts (that are on the back side of the park switch housing)-- towards the park drum and then reassembly the park switch cover and then check for a open between the two upper contacts on the park switch housing--you should see the circuit go open at the 1/10 bottom of the sweep of the wiper arms .If not--open the park switch housing again and again bend the floating contacts towards the park switch drum.

The park switch drum is driven off of the wiper motor by a worm gear and this rotating park switch drum causes the park cirlcuit to go open only when the wipers are at the bottom 1/10 of the windshield--the park area of the wiper arms.

It seems that the wiper motor has two battery circuits that energizes the wiper arms--one of which is controlled by the on/off switch on the dash and the other battery feed is from this park switch. If the park switch doesnt go open just at the bottom of the stroke--the wipers will never become intermittent and the wipers will never turn off after several strokes after turning on the washers and the wipers will never park at the bottom of the windshield!!

And what was confusing to me--about 10 percent of the time--the wipers would park before I did this fix. It would seem that these two floating contacts weren't pressing against the rotating park drum hard enough to make the circuit have continuity for 9/10s of the stroke of the wipers--and caused the wipers to stop in any part of the stroke of the wiper arm --and not park at the bottom.

Cheap fix--nothing to buy!! Just love these trucks!! Durable American engineering!!