Jaguar XJ40 Wipers Not Working, Wiper Motor
On these cars a wiper that won't park, stops mid-screen or won't switch off is almost always the small in-line park fuse, or the microswitch and cam inside the motor gearbox — not the motor. I'd thaw the blades, watch exactly how the arm stops, check the in-line fuse under the glovebox, then open the gearbox cover and clean or set the switch.
How bad is it · Garage, carefully
Don't set off in rain or snow until they work
Without wipers you can't see in bad weather. If they won't stop, unplug the connector at the wiper motor and drive on a dry day.
Which one applies to yours depends on your symptoms, your model year and what has already been done to it.
Likely causes, most common first
Read the check cost before the odds: a free check that rules a cause out beats a likely guess that costs money.
Blown in-line park fuse behind the passenger knee bolster
Parking, single wipe and the intermittent pause all run through one small in-line fuse next to the wiper control unit, separate from the main wiper fuse. When it blows, the wipers still run on the stalk but stop dead wherever they are the moment you switch off. A frozen or jammed blade is the usual way to blow it.
The arm stops instantly where it is when switched off; intermittent pauses mid-screen; a single flick doesn't complete. Often first seen on a frosty or snowy morning, with no warning on the dash.
Take off the panel under the glovebox on the passenger side and find the in-line holder on the red/grey and red/yellow wires. Fit a new fuse even if the old one tests good.
Fit a new fuse of the right rating: 5 A on early cars, 7.5 A, then 10 A from about 1990-91, when Jaguar uprated it. If a new one blows again, look for a short or a jam rather than going bigger.
Dirty, sticking or worn park microswitch in the motor gearbox
A cam on the gearbox wheel opens a small microswitch when the arm reaches rest, and the motor keeps running until it does. The switch isn't sealed, so damp and dirt make it stick, and the plunger wears. If it stays closed, the wipers keep going — even with the ignition off.
Wipers carry on after switch-off, add extra sweeps on intermittent, or park in a different place each time; worse in wet or frosty weather; a flick of the switch by hand finishes the sweep.
Disconnect the battery and remove the flat cover on the motor gearbox at the bulkhead (four screws). Look at the switch plunger for wear and check it clicks cleanly as the cam passes. Aim the spray straight at the switch plunger; it can take a day of standing to free.
Clean it with switch cleaner and treat it as a yearly job. If it's worn, the original Omron V-16-1C24 is unobtainable; an Omron V-15-1C25 SPDT of the same size fits. Some generic switches need their spade terminals narrowed. A smear of silicone grease helps keep frost out. A 12 A microswitch is a fair substitute for the 16 A original, as the small in-line park fuse blows long before the switch would burn. Worth fitting after a runaway: an in-line fuse in the motor's main feed, so pulling one fuse stops it instead of disconnecting the battery.
Park switch sitting too far from the cam
The switch sits on a slotted tray and has to be set so the cam opens it positively. A few thousandths too far away and the cam only half-operates it: the wiper overruns, sticks at the end of travel or never shuts off. Disturbing the cam while the cover is off has the same effect.
Fault came on after the gearbox cover was off, or the arm sticks at the far end of the sweep on interval while full speed is fine; on a wet screen the arm coasts past park.
With the motor unplugged, check pins 1 and 2 of the motor connector (red/slate and red/yellow) for continuity to ground: at park the switch should be open. Then run the motor with the cover off and watch whether the cam fully lifts the switch tab.
Loosen the tray screw and slide the switch slightly closer to the cam, or pack it with a thin card shim. When refitting the cam, hold the lower gear down so it doesn't ride up.
Wipers dead in frost: blade frozen to the screen
A blade frozen to the glass holds the motor still, and the washers keep working because they're a separate circuit. Running the wiper against a frozen blade is the classic way to blow the park fuse.
Below freezing, no movement on any setting, washers squirting normally.
Free the blade by hand before suspecting the motor.
Let the car thaw, then try again. A piece of card between blade and screen on frosty nights prevents it.
Chafed wire or a dirty connector at the motor
The 6-way black connector at the motor carries four wires: red/yellow, red/slate, blue and red. A worn patch of insulation on the motor lead shorts the park circuit, and the park fuse blows again within a few uses.
The park fuse blows repeatedly, often only on intermittent, even after a new switch and a different control module; or the wipers come back when the connector is wiggled. Slow, weak sweeps point at the motor earth.
Unplug, clean and refit the connector at the motor. Follow the motor lead and look for broken insulation where it moves or rubs. Renew the fuses in the right-hand box even if they look fine: a tired fuse contact gives the same random stops. For weak sweeps, run a jumper lead from the motor body to a good earth.
Repair the insulation or the wire. Cleaning the connector alone can cure both park and intermittent.
A cracked joint in the central processor
Interval and single-wipe timing come from the central processor. A corroded board with one loose solder joint keeps the wipers running, and it survives a new control module and a new motor.
Wipers won't turn off at the stalk and run on for up to a minute with the ignition off; single and intermittent wrong; slow and fast fine; the fault returns after new parts.
Rule out the park fuse, switch and cam first. Swap in a known-good wiper control module — two screws, one each side — before going into the processor.
Clean the processor board and resolder the loose joint. New control modules are no longer available.
Wipers and indicators dead together: the centre console fuse panel
One small 3 A fuse in the centre console panel feeds the wiper logic unit, the indicators through the processor, and the towing relay socket in the boot. A bad joint downstream of that fuse kills all three while the fuse itself tests good.
Wipers and indicators both dead, hazards still working, every relay and fuse testing fine.
Test for voltage after that fuse, not just across it. If the towing pack is fitted and also dead, that points at the shared feed.
Replace the centre console fuse panel with a spare. Reseat every connector you disturbed before trying to start the car.
Parks on the wrong side after a new motor
The park position is set by where the cam sits on the gear. A replacement motor can arrive with the cam or armature half a turn out, so the blade starts and parks on the passenger side.
Problem appeared straight after fitting another motor; the park point is wrong but always the same.
Mark the arm position on its splined post with tape, unplug the black connector and take the motor unit out (four screws).
Set the cam, or on motors where the gear is bolted to the armature the armature, to its opposite position. Pulling the park fuse lets the stalk stop the arm where you want while you set it.
Split outer cam ring or a gear loose on its shaft
The park cam is a plastic ring pressed onto the drive gear, and it cracks at its rectangular cut-out. Once split, the inner drive turns without carrying the cam round, so park becomes random. Forcing the arm against the scuttle or ice is the usual cause.
Random park that comes back even with a new switch; a blade that parks too high after it was forced; a weak, hesitant sweep from a gear slipping on its shaft.
With the gearbox cover off, look at the outer cam ring for a crack and check that the cam and gear turn together with the shaft. Check the arm is tight on its splines too.
Worth trying: drill the ring and pin it with lengths of music wire, then glue and cover the join with epoxy; pin a loose gear to its shaft. Broken plastic gear teeth can be rebuilt with thin superglue packed into baking soda, pinned for strength. An arm that slips on the screen needs its nut under the cap tightened onto the tapered splines.
Wipers dead at every speed: the relay module behind the left headlamp
The wiper relay is a separate module behind the left headlamp — module E in the 1993 electrical guide, DBC11206 on later cars. Modules of this type crack their internal joints, and the motor gets no power on any setting.
No wipe at any speed, washers still squirt, fuses good, no 12 V at the motor connector.
With the ignition and stalk on, look for 12 V out of the relay module at the motor connector. If the module gets its control signal but nothing comes out, it's the module.
Worth trying: resolder the module board or fit a used one.
Burnt-out wiper motor
A motor that has been strained against a stiff linkage or a jammed blade overheats. When the armature and field coils go, it draws enough to blow the main wiper fuse (15 A on 1990–91 cars, 20 A from 1992) after a few sweeps.
Two or three sweeps, then it stops and the main wiper fuse blows; 12 V reaches the motor; often after an earlier park fuse failure.
Check the linkage and arms move freely by hand with the motor disconnected, then have the motor tested on the bench.
Worth trying: a reconditioned or used motor; check the mechanism moves freely before fitting it.
The order to check them in
The point of the order is money: each step either rules a cause out or makes the next one worth doing. Green is free, amber costs a little, red is the one to arrive at last.
Free the blades and watch how they stop
If it's frosty, thaw the screen first. Stops instantly when switched off: the park fuse. Wipes on, then stops at random: the switch or cam. Same wrong place every time: cam position.
freeCheck the in-line park fuse
It's behind the passenger knee bolster under the glovebox, beside the wiper control unit. Fit a new one even if the old one looks fine, at the rating for your year.
a fuseOpen the motor gearbox cover
Disconnect the battery first. Clean the microswitch, look at the outer cam ring for a split, and check the arm is tight on its splines.
freeSet or replace the microswitch
Slide it a little closer to the cam or shim it; if the plunger is worn, fit an Omron V-15-1C25.
a few poundsClean the connector and check the motor lead
If the park fuse keeps blowing, look for broken insulation on the wire from the motor.
freeWipers dead at every speed
Look for 12 V at the motor connector with the stalk on. None: the relay module behind the left headlamp, or the centre console fuse panel if the indicators are dead too.
a test lampProcessor or motor last
Swap the control module for a known-good one before resoldering the processor; replace the motor only if it blows the main wiper fuse or the bench test fails.
a used part or a reconditioned motorWhat it usually isn't
Don't spend money here first:
If none of this finds it:
On jagaux.com
- Jaguar XJ40 Turn Signals Not WorkingIf the indicators died at the same time as the wipers.
- Jaguar XJ40 FUSE 1 or FUSE 2 FAIL WarningIf a fuse-fail message comes up with the wiper fault.
- XJ6 (XJ40) fuse boxesWhich fuse feeds the wipers on your year — other years from the same page.
- Jaguar VIN decoderConfirm your exact model year, engine and factory options before ordering parts — free.
Ratings, fuse numbers and torque figures vary by model year and market. Read the legend on your own car before pulling anything, and use the figures in the manual for your car, not the ones in a video.
Check your VIN: exactly which car you have and which bulletins apply to it.