Jaguar XJ-S

Walter Acker IV undertook the challenge of replacing the problematic Lucas wiper motor on the Jaguar XJ-S with a motor from some other car, and submitted the following report.  Note that Acker's car is an early model that came with the early Lucas wiper motor with a parking solenoid, but that really shouldn't make any difference; his method should work equally well to replace the later Lucas that reverses to park, and possibly even to replace the much later Electrolux motor.

Perhaps the most attractive feature of this retrofit is getting rid of that silly plastic gearwheel and push-cable mechanism in favor of a more rational tie-rod linkage.  Acker provided a pic of his OEM assembly for comparison:

I started looking at the wiper system and tried to devise an improvement to this poorly designed system. I first had to look at various systems to see how they worked so that I could see if I could devise an improvement to this system. What I found out was that the wiper arm pivots are about 19 inches apart on a Jaguar XJ-S and that it comes straight out of the grille assembly. Once again I went to the salvage yard to look for a possible motor and linkage assembly that might be usable in a Jaguar. I found that the linkage assembly from a 1976 Ford Courier pickup truck that is about 21 inches, and also used in an 82 to 84 Mazda B2000 pickup trucks. What I like about this system is that the wiper arm pivots are actually straight so that it is a very desirable system for use in the Jaguar.

Modifications to Jaguar grille

1. Run a 10-32 tap down the threaded holes of the grille; be careful as the grille is made of pot metal (soft and brittle). Purchase some 10-32 X 3/8 long screws for the new motor mount bar to the grille.

2. At the wiper arm actuator holes of the Jaguar grille grind the bottom of the pivot holes in the grille which is on the underneath side to the enlarged area that is slightly indented from the bottom of the pivot holes of the grille. The reason for this is that the new actuator pivots are a little shorter in length.
Actuator pivot for drivers side that also has a ball hook to allow the motor to move linkage:

3. The holes are larger in diameter than the Mazda/Courier pivots so I went to a local hardware store and purchased some plastic sleeves to help center the Mazda pivots in the Jaguar grille. The size was 5/8 outer by ½ inner, I used 4 of them total namely 2 on each side. These spacers are slightly longer than the distance of the grille holes. I had to grind a little off of plastic sleeves so that they would not interfere with the tightening of the Mazda pivots to the grille. The fit of these sleeves is not perfect, but since they are only to help center the pivots it is not a problem.

Modification of Mazda wiper bar linkage
1. When I took the wiper linkage from the car in the wrecking yard, I took all of the linkage, but the brace for holding the motor can not be used, as it is too big to fit in the Jaguar. This is one part that the Mazda no longer makes anymore.
2.  Remove but do not discard the mounting plate as yet because you may need it to draw the mounting holes in the new mounting bar.
3.  I purchased some aluminum material; the piece that I got was ¾ x 1/16 thick x 36 inches long of aluminum flat stock the local hardware store.
4. Cut the cross bar of the linkage that actuates the two pivots so that you mount the pivots in each pivot hole; the bar is hollow.

5. I purchased a black iron round bar that was 3/8 inch in diameter 4 feet long and cut approximately 6 inches to insert inside of the 2 ends of the wiper actuating linkage
6. Align the pivots so that the pivots are almost parallel. The Ford Courier uses the same linkage, but there is a difference namely balls on the pivots are plastic as opposed to Mazda, which are metal. After you assemble the linkage, test run the linkage under the grille by hand and be careful as the first time the linkage was in use the passengers side hit the brace that holds the grille down. The cure for this problem was to lengthen the linkage bar slightly so as to lengthen the linkage slightly so that it would no longer hit the brace. Retest the linkage system and the next problem was that the drivers side now hit the drivers side brace, the cure for this was to lengthen the actuating lever from the motor to the linkage system as it controls the drivers side alignment.
7.  The best way to align the pivots for is to position each pivot at exactly vertical for the welding process when installed into the Jaguar grille. When you are welding the bar together you need some type of heat protection for the grille. Use the inverted grille to set the points that you weld the new linkage together.
 
 

MOUNTING PLATE/ BARS         (motor)

1. Bend the new mount bar slightly then drill one hole and attach the end of the bar to the back of the grille.
2. Make an almost 90 degree bend upwards after you clear the assembled bar linkage.
3. Make another bend about 80 degrees just high enough to allow the motor to clear the grille assembly
4. Mark the mounting bar so that you can attach the motor to the bar.
5. After making the first hole, temporarily attach the motor to the bar and make a mark a place to drill the second hole to attach the motor to the bar.
6. If the bar interferes with the gear motor housing pivot, grind a little of the bar away to provide access of the second hole of the motor/gear unit
7. After making the second hole for the motor, attach the motor to the grille and then bend the bar another 90 degrees to bring the bar down to the grille.
8. Now bend the bar another 90 degrees so that you can drill the last hole of this bar so it can be attached to the Jaguar grille.
9. Now the second bar system will actually have to be 2 bars as the motor is offset too far to make only one bar for each of the remaining holes that are the mounts for the motor.

You can see the shortened rod from the actuators of the wiper linkage
The rod from the motor to the linkage is also shortened
On the right side you will also see the off white connector from the donor motor to the jaguar wiring

NOTES:
The only tools that I used to bend the bar mounts were a hammer and a vise so they do not look pretty, but are completely functional.
 

Important notes about the motor
The electric motor that I used was actually from a Ford Courier, the reason for this is that the Courier motor is smaller and fits the area under the Jaguar grille easier.

The linkage was from a Mazda B2000 pick up truck. The reason for the use of two different brands is that the Mazda uses a larger bolt pattern on the motor, the space under grille is rather limited in available space.

The motor has 2 speeds and a self-park feature built into the motor/gear system.
The motor as it comes from the salvage yard comes with a rain cover already installed onto the motor/gear system.

Actuating lever

The actuating lever goes from the motor to the completed linkage. It will also have to be shortened and bent slightly as the motor is not exactly on the same plane, but at a slight angle to the bar linkage.

Arms
The Courier wiper arm with the recess for the acorn nut to hold the wiper onto the actuator:

Another picture of the wiper arm with slight bend in it to allow the blade to sit lower on the windshield:

Wiring of motor
The jaguar has 5 wires to the motor for various operations. I did not use all the available wires, as the self-park feature of my car was not working at the time of this modification.

What wires that I did connect were as follows

Jaguar wires                                   Mazda wires                     uses

Pink/green                                    Green                                  B+

White/green                                   Green/Red                        Fast Speed

Black/green                                   Green/white                      Slow Speed

The rest of the jag wires                there was one wire
 were unused but I left                  which was the auto
 them for later work on                 park system that I will
 on the auto park                          fix at a later date
 system

After all the wires are connected test run the new system to check that all the speeds work properly. The next thing to verify is that the wires will clear the new linkage/ motor system so that there will be no interference between them. When I did this there was interference so I had to run the wires between the motor and the grille to keep them away from the linkage. The best way to check for any interference is to temporally remove the wire mesh grille that is under the normal grille and then reinstall it after all the work is done satisfactorily.