A Look Inside--Rear Wiper Motor

[TheJackal]

I had to replace my rear wiper motor again and this time, I went with a new Motorcraft that I actually got a good deal on online. After installing the new one, I decided to take apart the old one as there was no core charge.

This was a new Dorman motor which worked for about a year. That was 6 months longer than the reman motor, but still short of expectations.

And the other side:

I was really curious to figure out why these things don't last. Four screws hold on a metal cover onto the case. After removing them, we can see:

You can see the contacts and the metal plate on the gear which comprise the sensing mechanism.

After removing the gasket you can clearly see a lot of white grease accumulating on the sides. It's been pushed out of the area where the gears mesh.

I had this happen once before on an old, cheap portable CD player back in the 90s. It had a metal worm gear that moved the lens carriage, which had a plastic piece that rode in the groove. After about 6 months of use, the CD player began stopping at random in the middle of songs and make all kinds of noise. After opening it, I found the same thing. The carriage would bind in the gear.

You can't tell in this pic but the gear has some damage from the worm gear skipping against it.

So, there you have it. The answer to why reman motors are never as good as Motorcraft and another one of life's mysteries solved. (tho I don't know what grease they use in the Moto one to avoid this)

 

[gijoecam]

I think I'm on my 8th motor in 5 years... I replaced it with a NEW one last time around (Dorman) and it's got issues too... travels farther than it's supposed to and won't come out of park on its own. I'm gonna put a Motorcraft in when I get around to it.

On the plus side, I can take the old motor out in about 2 minutes!

 

[TheJackal]

travels farther than it's supposed to...

I had the same problem with this one. After looking at it I wondered if that white piece on the end of the worm gear was some kind of adjustment... but I don't think so as the PCM only knows to reverse based on the metal plate contacts.

 

[gijoecam]

I had the same problem with this one. After looking at it I wondered if that white piece on the end of the worm gear was some kind of adjustment... but I don't think so as the PCM only knows to reverse based on the metal plate contacts.

Agreed, but it's the GEM not the PCM that controls the relays for the wiper.

 

[Dennis1188]

Problem solved...

 

[TheJackal]

Agreed, but it's the GEM not the PCM that controls the relays for the wiper.

Whoops, must've had yet another brain fart there. :biggthump

 

[Busadude]

my rear wiper on my 2002 wont turn off after i turn it on even with the key turned off , the only way to turn it off is to open the hatch and shut it and the jarring turns it off any ideas what might cause this problem ?

 

[ThePhoenix]

I never use mine....maybe I can remove mine too!

 

[coonerboy]

As a side note for anyone having trouble with their rear wiper, check your rear hatch glass lock adjustment. The rear wiper has a interlock in the hatch glass lock that prevents the wiper from running if the glass is open. If this lock is out of adjustment it will cause the wiper to not run. One symptom of this would be you have to push the button very hard to get the glass to open. If you have this problem and your wiper dont work or works intermittently you need to adjust the hatch glass lock. I just did this last night and wish i took pics while i had it apart, but its a pretty easy fix.

 

[myerswg]

Do you have instructions for adjusting the glass lock? I have not tried that since the push button is not hard to operate, but clicking sound still comes from rear wiper motor. I can't seem to find any more info on your fix.

thanks