Jaguar XJ-S. Service manual — part 155

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There have been three distinct types of wiper motor used in the XJ-S. In the earliest models, a Lucas wiper was used
that incorporated a parking solenoid inside that pulled the wipers into a parking position that was beyond the regular
wiping limit. Later models used a different Lucas motor that had no parking solenoid but ran the motor in reverse to
park. Finally, around 1987 an Electrolux motor was introduced.

Note that Jaguar made a regular practice of replacing the early solenoid-park Lucas motor with the later reversing-park
Lucas motor. They do not simply plug in, so Jaguar dealers were provided a “blue box” that allowed the earlier
controls to operate the later motor.

BLADES: First, a clarification of terminology. “Wiper blade” means the entire apparatus at the end of the wiper arm.
The little rubber strip that actually contacts the glass is called a “refill”. Don’t blame me, I didn’t come up with this.

The OEM blades on the author’s ’83 were really garbage: a simple pair of levers with a spring at the pivot point. These
were replaced with some Anco aftermarket units which are much better, having a multiple beam arrangement to
distribute the load over the blade edge.

The OEM blades on the ’83 have a pin protruding from the side of the center hinge that clips into the side of the arm. A
perfectly workable attachment, but unfortunately largely unheard-of today. However, it was common enough at one
time that some aftermarket blades came with little pins that would snap into the blade and allow it to be attached to
these arms. This is no longer popular, but many auto parts shops still have a collection of these pins in a drawer behind
the counter. After all, 99% of the customers buying replacement blades didn’t need the pins and just tossed them over
their shoulders on the way out of the store. Once you have a pair of pins, you’re good for the life of the car; the pins
won’t wear out, so you can use them with whatever blades you ever install in the future. Most of the pins are steel, but
some were stainless steel; if you’re going through a box in an auto parts store, you might opt to keep looking until you
find a pair of the stainless ones.

The OEM blades were both the same length, but when I was buying aftermarket Anco blades I installed a 14” blade on
the driver’s side and a 15” blade on the passenger’s side. The 14” blade allows the driver’s side wiper to park without
contacting the A pillar. Also, having wipers of different lengths reduces the tendency to chatter -- which is one reason
why many modern cars come with two different size blades from the factory.

The Anco blades held the edges against the windshield better and wiped better when it was raining -- but when it
started to dry up, the wipers wouldn’t park! The motor didn’t have enough ooomph to move them. This led to a relay
installation, as described on page 625, which fixed that problem.

Reportedly the OEM wiper blade design was changed shortly after ’83.

WIPER MOTOR REMOVAL: Removing the wiper motor involves removing the entire intake grille assembly in front
of the windshield. It doesn’t look hard, but there may be trouble; the two fasteners closest to the windshield actually
involve a rubber isolation mount, and trying to unscrew the nut may just rip the mount apart if you are unlucky today.
Fortunately, it isn’t too difficult to improvise a replacement mount scheme using a small bolt, a couple nuts, and a
rubber grommet or two. It probably wouldn’t be a good idea to rigidly mount the grille, though; Jaguar probably used
the rubber mount for a reason.

WINDSHIELD WIPER MOTOR COVER: Under the grille, Jaguar provided a cover over the wiper motor to keep the
rain off. If you’re wondering where your original cover went, you need to read about water leaking in through the A/C
system on page 463. This plastic part does not hold up in sunlight.

Providing a new plastic cover from Jaguar over the assembly would help for a while, but then it will just break up and
plug the drains again. The aluminum tape suggested below is likely to be the prime protection for the motor in the long
run. This author didn’t even bother installing a cover and simply relied on the tape, painting it black so it would look
OK from outside the car. It has worked for a decade.

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Chuck Sparks suggests that you can buy a new cover and fiberglass it before installation to render it impervious to
sunlight. Just coat it with resin, sprinkle on some loose fibers, and apply another coat of resin. Trim the edges up to
make it look pretty, then paint it.

Jim Belkoff says, “John's Cars sells a replacement cover made out of genuine American plastic. I think it's worth the
nominal cost.” John’s Cars is on page 715.

Chuck Roach says: “I went to my Jag dealer to pick up a new cover and the parts/service manager told me to forget it
and just use an old one-gallon plastic bottle and cut it to fit and hold it in place with cable ties. Worked great. Will
probably last as long as the original.” I disagree; it’s likely to last a good deal longer than the original.

Of course, you could probably fashion a cover from a thin piece of aluminum. Or find a metal can about the right size
and shape and cut it out to make a metal cover. Or fashion a cover from a section of aluminum rain gutter. Or simply
coat the motor with a layer of mastic. The possibilities are endless, just use your imagination.

WINDSHIELD WIPER MOTOR REBUILDING: The housing of the Lucas wiper motor is not waterproof, and it’s
sitting right under the grille, exposed to the elements. To protect it, Jaguar provides a plastic cover over the motor to
keep water from falling on it. There are also two large drains from the wiper motor compartment out through the
engine compartment and out into the front wheel wells that should prevent any standing water from accumulating in
this area. Unfortunately, the cover is usually history (see above), the compartment drains are often plugged because
that’s where the cover ended up (see page 463), and the wiper motor has ceased functioning due to water damage.

If you have trouble with the wiper motor, it’s not too difficult to rebuild. The ROM doesn’t include any instructions for
overhaul, but the Haynes manual does. Note that the instructions in the Haynes, including Fig. 10.101, don’t accurately
reflect the Lucas reverse-park motor found in the author’s ’83; perhaps they are more representative of the earlier
solenoid-park motor.

Typically, a wiper motor “assembly” consists of the motor itself and the gearbox, with the gearbox integrated with one
end cover of the motor. The instructions in the Haynes manual talk as much about getting the gearbox apart as the
motor, but really you can usually tear apart one without disturbing the other. If it’s the motor itself you wish to
disassemble, it’s a simple matter of removing two long screws. Note that the illustration in the Haynes shows the
housing (it’s called a “yoke” in the Haynes manual) as a single piece, while the author’s ’83 has a cylindrical case plus
a separate end plate. Once the housing is off, the rotor can be removed by “unscrewing” it, allowing the worm gear to
disengage without moving the wipers.

While apart, remove any accumulation of rust off the large cylindrical diameter of the rotor, the surface that passes very
close to the magnets in the cylindrical can. You can use sandpaper; it’s just iron. Use a phosphoric acid-containing rust
treatment on this outermost surface to stabilize it and help prevent future rust, but be careful not to get the acid on
anything else -- the wiring, the commutator, etc. Also clean all rust particles out of the cylindrical can, which will
require some patience since they will stick to the permanent magnets inside so you must grab each particle to remove it.
Masking tape is helpful; just stick it down and peel it off and it takes away a layer of the ferrous dust.

Clean up the brushes, which tend to jam when they’ve been wet for a while; make sure the brushes slide freely. If the
brushes are worn (too short), replace them; there’s no need to go looking for genuine Jaguar parts, just find any place
that sells electric motor brushes (vacuum cleaner repair shops, starter/alternator shops, etc.) and buy some brushes that
are a bit larger and file them down to fit. Carbon takes only seconds to file to size, although these will require some
care since each brush has slots down the sides. The original brushes have brush, spring, brass guide and wire all
bound together as one piece, but you can reassemble with separate generic pieces any way that forms a proper electrical
connection. Note that the “third brush” in the Lucas wiper motor is a tad unusual in that it has one half of the tip cut
away; make a similar notch on your homemade replacement.

If you’re not up to that sort of work, Walter Acker says, “The brush plate is available from the dealer. It is normally a
special order that takes time to get.” Apparently, the same brush plate fits either the Lucas solenoid-park or the Lucas
reverse-park motors.

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Usually the best thing to do with the commutator, the segmented copper arrangement on the rotor that the brushes
contact, is to leave it alone. However, if it’s gouged, eroded, or otherwise in need of attention, the thing to do is to
chuck it up in a lathe and file, grind, or otherwise machine the surface to clean it up, and then polish it as smooth as
possible. Smoothness is good for brush life.

Use an ohmmeter to check for continuity at the commutator. There should be some continuity between any two
segments, so you can check them all quickly by just connecting to any one segment and then check for continuity to
each of the others from there. Also check that there is no continuity between a segment and the steel core of the rotor.
If there’s any segment that lacks continuity or a short to the core, you probably won’t be able to fix it yourself; either
contact a motor repair specialist for guidance or just buy a new wiper motor.

Lubricate the bearings with something that won’t dry out and get gummy. Synthetic motor oil is probably as good a
lubricant as you will find. However, take care not to get too generous with the lubricants at the commutator end of the
motor; if the lubricants ooze their way onto the commutator, it’ll screw up the motor and you’ll have to come in here
again and clean it up.

The most difficult part about reassembling a commutator motor is holding the brushes in a retracted position while you
slide the rotor into place. Fortunately, on this motor the rotor goes in first and the case goes on afterward, which makes
this task easier than on motors where it all must go together at once. Still, the fact that there are three brushes may
make you run out of hands; you might use small pieces of wire to hold the brushes back during assembly.

If the long screws strip out of the threaded holes in the gearbox housing, you can install slightly longer screws and put
nuts on the back side.

This being a worm screw drive system, there is a setscrew and locknut on the gearbox that contacts the tip of the rotor
shaft. When assembling the motor, loosen the locknut and back the setscrew out a bit. After the motor housing is
securely bolted into place, tighten the setscrew until it snugs up, then back it off a quarter turn and tighten down the
locknut.

After reassembly, it wouldn’t hurt to seal the top of the motor with aluminum tape (available where air conditioning
supplies are sold -- it’s used to seal ductwork) to help prevent water from getting in. You also might want to cover the
center bump on the end plate; on the author’s ’83 there’s a thrust insert behind the bearing that sticks out a hole -- it
doesn’t move, but it’s not sealed. Don’t cover the bottom of the motor; leave the openings uncovered on the bottom so
that condensation drains out. And, of course, attend to the cover and compartment drain problems so you don’t have a
repeat of your troubles.

The solenoid-park Lucas motor, the reverse-park Lucas motor, and the Electrolux motor differ in detail, but the same
type of repair and renovation should work on each.

WIPER MOTOR MAGNETS: Herman Green: “I took the motor apart and found that one of the magnets had come
loose and had jammed the armature. The magnets are glued in with what seems to be some kind of silicone. Rust had
crept under the bond and it gave up. I marked the location of the magnets with a file and measured the distance from
the end of the housing to the top of the magnet, so I could put them back in the correct position. I also marked the
magnets as to their location and orientation. If they're put in wrong, the motor will either run backwards or lock up. I
then removed the magnets and cleaned them and the inside of the motor housing with a sanding flapper wheel in a drill
motor. I then mixed up some JB Weld and glued them back in place. When gluing the magnets in, use a clamp of
some sorts to snuggle them in tight. If not, you may not be able to get the armature back in! Once cured, I painted it
with rustoleum to prevent further rust, and put it back together. Works great and should last a long time.”

The author had the same problem. The white glue used is apparently just fine, Lucas didn’t screw up there. The
problem is water damage, due to the various water problems already noted -- lost motor cover, jammed compartment
drains, etc. Eventually the motor case rusts behind the magnets, popping the glue loose.

Interestingly, the author’s motor still ran with one magnet loose. The magnet is somewhat trapped between the case,
the rotor, and the two long bolts holding the motor together. It can slide back and forth a little, but can’t go anywhere.

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Apparently the motor just ran with the rotor rubbing on the face of the magnet without damaging anything. Of course,
it didn’t run well and occasionally it didn’t want to start, which is why the overhaul was undertaken.

If you’re as lucky and the magnets are intact, you can glue them back into place with JB Weld as Green described. If a
magnet is neatly broken into two or three pieces, you can still fix it -- just glue the pieces together with JB Weld. If
drop a magnet on the garage floor, though, it will probably shatter into hundreds of pieces; the magnets are made of
ceramic. In this case, you’ll be needing a new motor.

If only one magnet came loose, just put it back in directly opposite the one that’s in there. If both are loose, you need to
figure out where they go. Since the author has been in there, some specific guidelines for where the magnets go in the
Lucas reverse-park motor are given on page 624; if your motor is the same, use those tips. If your motor is different,
try the ideas below.

Since the magnets can’t go anywhere, you should take note when taking the motor apart. If both magnets are loose,
immediately stop what you’re doing and mark which magnet goes in which side of the case. Installing them backwards
will make the motor run backwards, and that means the reverse-park system will be trying to park when it’s supposed to
be running and run when it’s supposed to be parking and the like; things will be all screwed up.

If you failed to note which magnet goes in which side, you might as well try the guidelines for the reverse-park
provided on page 624; the chances of being correct are at least 50/50, perhaps better if Lucas kept the same magnet
orientation from model to model. If you reassemble everything and it doesn’t work right and you figure you’ve glued
the magnets in backwards, there is one possible easy way out: remove the screws from the motor and rotate the entire
case 180º and put the bolts back in. If there is an alignment notch or keyway, you may need to file a new one -- but the
author’s ’83 didn’t have any such devices, only an alignment mark. So you will be deliberately not lining up the
alignment mark.

Other guidelines for magnet reinstallation: they should be equally spaced from each other within the case. When the
motor is assembled, they should be aligned with the pair of brushes that are directly opposite each other. Obviously,
the long bolts will end up between the magnets. Axially, the magnets should be centered over the core of the rotor, so
with some careful measuring you should be able to locate them well enough.

If you only had to reglue one magnet, you know you really want to go ahead and knock the other one loose and reglue
it while you’re in there. I recommend against it. Shove on it a bit and see if you can get it to pop loose, but if it doesn’t
come off easily just reassemble the motor and forget about it. It’s not all that difficult to get this motor apart and reglue
it if it comes loose later. But if you get forceful trying to get that magnet loose, you’re only too likely to break it -- and
then you’ll need a new motor.

WINDSHIELD WIPER PARK POSITION: On the author’s ’83, the wipers park to the left. Apparently some other
cars have wipers that park to the right, but there doesn’t seem to be any rhyme or reason to it.

The XJ-S wiper pivots are symmetrically located in front of the windshield, unlike any automobile on which an
engineer thought about it for two minutes before designing it. As a result, the tip of one wiper bumps into the
windshield frame when parked. Page 214 in the Haynes says to install the arms so the blades are parallel to the bottom
edge of the screen when parked; that may work on the XJ12 but you really can’t do that on the XJ-S on the side the
wipers park pointing towards; the bottom end of the blade hits the chrome trim and the tip hits the A pillar. Avoiding
these contacts requires positioning that wiper to park up high so it doesn’t hit the frame; in the “Supplement for Later
Cars” section, the Haynes actually provides an illustration with dimensions for positioning the wipers this way.
Unfortunately, it looks stupid and obstructs the line of sight.

One way to improve this is to modify the wiper arm that points toward the A pillar to be shorter. This requires carefully
unfolding the sheet metal where it is wrapped around the strut and drilling out the rivet just above the spring
attachment. Then the strut can be cut about an inch shorter, drilled and bent to form a new spring attachment, a new
rivet hole drilled, and then the strut can be reattached with a new rivet (a pop rivet will do) and the sheet metal re-
crimped around the strut. A little flat black paint, and no one will know the original design was so poor. With the
shorter arm, the wiper can be positioned much closer to the bottom of the windshield. Note that the shorter wiper will
not reach as far toward the top of the windshield either, but this doesn’t seem to pose a problem.