Windshield wipers not returning to bottom

[KornTruck2]

Hey guys, i got a 99 ranger. My wipers are acting funny. On the lowest delay, they work fine, they swoop left then right. Then they dont work till i go to min/max (not in delay). Some say the turn signal knob, some say motor. Is there a relay or somekind of module thats controls it? Could it be a GEM module? Please and thank you!

 

[sgtsandman]

Usually, the problem is the multifunction switch, ie the turn signal stalk with the wiper control on it.

Wiper motors go bad but it’s not super common.

 

[19Walt93]

The park function- what you called returning to the bottom- used to be internal to the wiper motor and I suspect it still is. Intermittent wipers energize the park function. I don't remember the last time I saw one fail so do some diag before replacing the motor unless you have a spare.

 

[KornTruck2]

I had a bunch of 25 year old relays failing..

 

[RonD]

Yes, there are 2 wiper relays in the engine fuse box, easy to get at and swap out

Yes, Park function is in the wiper motor
Wiper motor has a wheel that spins, on the edge of that wheel is a post
The post contacts a switch at one spot and that cuts 12volt to wiper motor
This PARK switch has 12v full time when key is on

When you select intermittent/delay wiper function a timer sends momentary 12v to wiper motor so it starts the blades moving, and PARK 12v takes over, when the wheel turns one full cycle the switch is pushed open and 12v is cut, wiper blades parked
Then timer sends 12v again and wipers start again
Timer length is varied by dial on multi-function switch

Wiper motors have 2 speeds
Wiper Low sends 12v full time to wiper motor but when you shut it off the PARK 12v takes over until wipers are parked
Wiper High does the same

In 1995-2003 Rangers the GEM Module is the middle man
Multi-function switch wiper controls/wires all go to the GEM module
GEM module connects to the relays and wiper motor
So there is an extra layer where things can go wrong