Wipers not going back down

[shotrod69]

1987 suburban 3/4 ton
My wipers stop and the end of the “up” travel. If I push them back “down” it will cycle and get stuck in the up position again.

I believe that it is the gears in the wiper motor and that the wiper motor needs to be replaced. All I would like to know is if my diagnosis is correct or if further investigation is needed. I am also seeing posts about wiper adjustment. I will read those when I get the new parts, but I believe that putting that procedure here will be good for those who come after me.

 

[Edelbrock]

Take the wiper arms off and reposition them on the post.

Or -

Won't go down when you want? Time for an upgrade - Trade her in for a newer model!

 

[83Stepper]

Try @Edelbrock's advice first. Could be as simple as when the arms were reinstalled, they weren't positioned correctly. Otherwise, it'll be the park position in the motor that's possibly wiped out. Easy enough job to swap out the wiper motor if the first option or repositioning the wiper arms doesn't work.

 

[gmbellew]

the wiper linkage is attached to the motor out 180 degrees. disconnect the linkage, move the wipers down, turn the switch on and off so the motor parks, reattach linkage to motor with wiper in park position and motor in park position.

only 1 time does a person install a new wiper motor without cycling the switch to make sure it is in the park position. I know from experience.

 

[shotrod69]

the wiper linkage is attached to the motor out 180 degrees. disconnect the linkage, move the wipers down, turn the switch on and off so the motor parks, reattach linkage to motor with wiper in park position and motor in park position.

only 1 time does a person install a new wiper motor without cycling the switch to make sure it is in the park position. I know from experience.

The problem I explained just started happening. They’ve been working fine for the past 5 years and 60k miles

Edit: How does the wiper mechanism actually work? I work on Peterbilts and the just spins all the way around and uses sensors to know when to stop.

 

[Snoots]

Likely the Park Position Switch. Easily cleaned.

 

[gmbellew]

The problem I explained just started happening. They’ve been working fine for the past 5 years and 60k miles

Edit: How does the wiper mechanism actually work? I work on Peterbilts and the just spins all the way around and uses sensors to know when to stop.

the motor spins around and there is a plastic disk with a cam that lifts up the park switch to break contact at the bottom of the stroke. thats why if you put the motor on without checking that the motor is parked, like I did that one lesson learning moment, the wipers won't park properly.

couple things could have happened. first, the park switch could be at fault or the internal cam mechanism slipped. second, the nut holding the wiper linkage to the motor could be loose and allowed the motor to spin 180deg before it caught the linkage again.

either way, you will probably need to minimally peak into the cowl area while the wipers are being operated to visually check. it is possible to check the attachment to the motor with the motor installed, but i always find it easier to just unbolt the motor and pull the connection back through the firewall. there is enough slop to do it.

is it stopping exactly at the highpoint of the swing or in the middle of the windshield?

 

[BigT]

As suggested above, clean all the electrical contacts on the motor really well and try it before you pull anything apart. If it does nothing, then at least you've ruled that out.