Wiper motor R&R

driller

El Presidente
Staff member
This post will serve as a how to guide for the removal and replacement of a wiper motor on a Gen 1 Mark VIII and I'm sure it would be very similar on a Gen2.

I'll use the text of the manual and ad lib with some pics and text in italics.

Wiper Motor

When installing the drive arm to a new motor, follow the instructions included in the new motor kit. (The wiper motor I installed was a new Motorcraft unit, P/N F7LZ -17508-AB, complete with park mechanism. There are purportedly a shortage of wiper motors and there have been accounts of the "drive arm" or "park mechanism" NOT being included with a new wiper motor. Also, early '93 and some '94 Mark VIIIs had wiper motors with 2 harness plugs versus the later models with one harness plug.)

CAUTION:
The internal permanent magnets used in the wiper motor are a ceramic (glass-like) material. Care must be exercised in handling the motor to avoid damaging the magnets. The motor must not be struck or tapped with a hammer or other object.


Removal and Installation

1. Turn ignition to the run position. Turn on the windshield wipers and cycle wipers to the mid-wipe position (straight up) and turn off the ignition. (NOTE: This only helps if the wiper motor functions - with a dead motor you cannot move the wipers.)

2. Disconnect battery cable.

3. Remove LH and RH wiper arms. (This is done quite easily but is difficult to explain without pics. Note the pic below, the arm is down and you can see a small tab which is the lever to lock the arm up off the glass.)

IMG00069-20100102-1611.jpg


(To remove the wiper arm, you lift the arm off the glass and pull out on the locking tab and release the arm. The locking tab will then be holding the arm tension with the wiper off the glass.)

IMG00070-20100102-1611.jpg


(Then it is a simple matter of pulling the wiper arm off the pivot.)

IMG00071-20100102-1613.jpg


4. Remove cowl top to hood seal.

IMG00072-20100102-1613.jpg


5. Remove LH and RH cowl vent screens. (It is best to lower the hood for this step. There are 7 philips head screws - 4 on the RH side and 3 on the LH side.)

wiper1of2.JPG


IMG00073-20100102-1615.jpg


You will need to disconnect the washer tubing from the cowl vent screen covers.

IMG00074-20100102-1624.jpg


6. Remove four retaining screws and washers and the cowl top extension. (RH side)

IMG00079-20100102-1727.jpg


7. Disconnect two wiring connectors from the motor. (Or one connector on later models. On mine we had already cut the harness when we were diagnosing the motor).

8. Remove five retaining bolt and washer assemblies and one nut from the wiper module. (Note to all - the one nut is below the wiper motor and attaches a bracket from the cowl to the firewall. It is a royal pain to access. So much of a pain, there was no good way to get a pic of it. It is item # 6 in the diagram below.)

wiper2of2.JPG


IMG00077-20100102-1628.jpg


(I find it helps to disconnect the engine wiring harness and move it out of the way.)

IMG00078-20100102-1657.jpg


9. Lift the module slightly to disengage the support bracket from the dash panel mounting stud, move the module sideways about 50.8mm (2 inches) toward the passenger side and remove the module from the vehicle. (Sounds simple but get ready to do battle.)

IMG00080-20100102-1754.jpg


10. Disconnect linkage drive arm from the motor crankpin after removing the clip.

IMG00081-20100102-1757.jpg


NOTE:
Check location of support bracket on module.

11. Remove the wiper motor's three retaining screws and remove motor from the module.(In the pic below, the top middle [already removed] and the bottom two bolts are the 3 retaining bolts for the motor. The top right is the bolt-hole for the bolt retaining the cowl assembly.)

IMG00082-20100102-1757.jpg


CAUTION:
Before installing the arm and blade assemblies to the pivot shafts, cycle motor and turn off wiper switch to ensure that the wiper linkage is in the park position. Refer to «Arm Assembly» , Removal and Installation for installation procedure.

IMG00083-20100102-1800.jpg


IMG00085-20100102-1802.jpg


12. To install, reverse Removal procedure.

IMG00086-20100102-2331.jpg


IMG00087-20100102-2346.jpg


IMG00081-20100102-1757.jpg


IMG00078-20100102-1657.jpg


IMG00074-20100102-1624.jpg


IMG00073-20100102-1615.jpg


IMG00072-20100102-1613.jpg


IMG00070-20100102-1611.jpg


IMG00069-20100102-1611.jpg
 
I could feel my hands bleeding already. How brittle is that wiring harness? Be my luck to fall off in my hand.
 
Glad you survived, it sure looks like a vocabulary exerciser as well.

That it was for sure. The nut for the bracket below the wiper motor required quite a few verbal expletives. Then the part about "move it 2 inches to the right then out to remove the wiper assembly" was a whole other round of vocabulary exercises. Going back together was no fun either. Especially after dropping the elusive nut for the bracket when trying to get it started on the stud.

Don't forget I had 7 wires to splice as well for the harness.

All in all, it was a fun day (yeah, right). I broke it up into segments to give my back a break as well. But now I can drive in the rain (if it ever gets above freezing here!).
 
Glad that you got the wipers working, and that it was indeed the motor, as I had my doubts.
 
Glad that you got the wipers working, and that it was indeed the motor, as I had my doubts.

LOL, me too on having doubts, because I spliced the wires and plugged it in for a test before I put it all back together. Evidently the other motor was mysteriously murdered in it's sleep since i can't remember the last time it was even used! :rolleyes:
 
Wow, looks like a lot of PITA work for a part that should be more easily serviceable. Nice write up. :cool:
 
LOL, me too on having doubts, because I spliced the wires and plugged it in for a test before I put it all back together. Evidently the other motor was mysteriously murdered in it's sleep since i can't remember the last time it was even used! :rolleyes:

It died of atrophy! You have to use things every once in a while, or they get lonely and quit. :(
 
I had to take my wiper assy out once to change my brake booster - total pain. Now, I think my wiper motor is bad. (wiper spindles start and stop erratically after about a min of use - it's either gonna be the motor or the module, but I think motor)

Anyway, thanks for the write up - I'll be making good use of it within the next couple of months! :)
 
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