HI,
My wipers work, but are rather under powered, being slow to move. They move way better when it rains 
Anyone know if this motor would work? It looks identical to the original.
Thank you.
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If you want your wipers to move like they mean it, I recommend installing relays. Rather than the power going through the stalk switch, the stalk switch merely energizes relays. Power for the wiper motor goes from the battery through the relay contacts and directly to the motor. I drew up a schematic for the wiring scheme for the XJ-S in my book, dunno for sure but the XJ is probably similar.
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Stout panel switch on the S1, Kirbertālike S2 E-type.
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Doesnāt matter how stout the switch is. What matters is how long and skinny the wires are. Presumably the panel switch isnāt far from the wiper motor, so thatās good, but itās only too likely the wires are too thin. Easy to check: Just use a VOM to check the voltage right at the motor to see how much voltage is lost on the way from the battery. If itās less than perhaps 10V, relays will help. I measured 7V at mine.
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Is it feasible to increase the voltage for the whole car? Modern cars charge a little higher, donāt they - now maybe the voltage regulator isnāt as accurate as new ones, so if a modern one was used it might give brighter lights, instruments and faster wipers - on a 14.4v drill battery my S1 wipers are definitely wiping very well even dry (why would anyone do that!)
I am sure though that with a volt less and the motor and the greasy parts in good condition the wipers would still do great. Maybe the grease is gone.
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Thank you Kirbert. I will get a looking at the skinniness of the wires from the switch. never occurred to me so appreciate the knowledge 
.
great call on the grease quota. Iāll check that too.
The switch panel fascinates me. that spaghetti junction like wiring is a feast for the eyes
The word is that optimal charging voltage at room temperature is 14.4V and drops off as temp rises. Optimal charging voltage at underhood temps is 13.6V. Older Lucas alts charged at 13.6V, period. Newer alts typically charge at 14.4V when the engine is cold and drop down to 13.6V as the engine warms up, based on a temp sensor inside the alt itself. A few alts go a step further and use a remote sensor mounted right on the battery ā which would be great in the XJ-S since the battery is in the trunk, it could charge at 14.4V all the time.
Another trick: The optimal charging voltage is at the battery terminals. Alts normally control the voltage at their output terminal, meaning the voltage at the battery is a bit lower due to losses in the wiring in between. Thereās a fix for that, too. Itās called a āsense wireā, and itās connected between the alt and the battery so the alt knows what the voltage is at the battery terminal. That way the regulator can boost the charging voltage to compensate for the losses in the wiring.
Both these changes boost system voltage, and will result in noticeably whiter headlights. Not sure itād do a lot for the wipers, though.
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At least on the SII is identical.
I installed relays and it made all the difference, same story with the electric windows.
I used the junction/plug of the wiper motor to connect all the relays so I didnāt have to fiddle with the wires on the stalk switch, and I can always unplug them and plug the wiper as original, great for troubleshooting if something goes wrong.
A new motor wonāt help if it hasnāt adequate voltage.
Greasing the cables made some improvement, but not much.
**
Itās a sort of inborn Jaguar āproblemā, Minder - they didnāt really consider wiping a dry screenā¦
I āthinkā the motor shown is any stronger than the original - and wonāt necessarily compensate for the power loss mentioned by others. Like bad connections and thin wires - and certainly old grease in the rack doesnāt help.
You may test with a jumpwire directly from the battery, and similarly from motor to ground, just to see the influence of wires and bad connections - and consider options. If it makes no difference; cleaning and lubricating the rack mechanisms may helpā¦a bitā¦
As an aside; upping the voltage at the motor by other means is questionable. Higher voltage from the alternator only works when it is running. And is sort of easily tested by reving the engine to see the effect on the windscreen wipers. A general increase of the alternator voltage is not advisable; it will be couterproductive for battery life and other electricsā¦
Frank
xj6 85 Sov Europe (UK/NZ)
**
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Going beyond the 14.4V provided by a modern alt is definitely ill-advised. But I installed a GM CS130 alternator on my '83 in place of the 75A Lucas it came with, and frankly I was surprised at the differences it made. I expected the headlights to be brighter when the engine was cold, but frankly they seemed brighter and whiter all the time, even as I was arriving home. Full disclosure, I had some serious e-fans moving air around under the hood, so it probably stayed cooler under there than most cars, and that might have caused the alt to stay closer to the 14.4V than the 13.6V.
But it made other differences, too. It seemed as though the battery was much better charged than before so the non-geared starter really zipped the engine over. Frankly, the whole car felt less āBritishā if that makes any sense; it felt bright and cheery with bright white interior lights, dash lights, windows that zipped, wipers that zipped, doors that locked with a stout click, etc., rather than the anemic electrics we have all come to expect from British cars. Of course, I had installed relays on windows, wipers, and headlights as well.
Oh, one other thing: The wipers and windows, all electric motors, worked better as soon as the relays were installed and as soon as the alt was upgraded. But they all continued to work better and better with use over the following few months. It was almost as though operating on low voltage for so many years had deteriorated them somehow, and running on full juice for a change was āclearing out the cobwebsā or something. An Italian Tune-Up for the wipers and windows! Iād be interested in hearing if anyone else noticed a similar effect.
Frankly, I cannot recommend an upgrade to a modern alternator highly enough ā but I donāt expect it to be the answer to your wiper issues. Relays should be the first step IMO.
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Makes sense.
The only time I ever use the wipers is when the engine is running and the windscreen is wet. Thatās me.
My S3 wipes fast enough for all kinds of rain (but I use RainX). The S1 I donāt know yet but it wipes well. If it was me Iād drive the motor directly and see how well it goes before removing anything. I would not remove anything or add relays.
The Road &Track article introducing the new 1968 Jaguar XJ6 described the wipers as having the Saint Vitusā dance.
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I know that they work by annoying the water away slowly but again mine work well so far. Maybe my expectations are low but apart from the too short blades to me it works well. Hm.
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Hawai Brit (?; - the only one I know passed away, sadly, some years ago and it was Jonathan Higgins from āMagnum P.I.ā),
instead of changing a good wiper motor Iād also address the voltage issue. Swapping the alternator has helped my car a lot. You can check your voltage under normal driving conditons at the cigar lighter - a trick I learned from Carl! - and at +14V I bet youāre a happy camper.
The other thing is the shaft drive that depends on grease. I doubt that the grease is gone, but am afraid that it has changed its properties over 50 years. The final issue is the spindles. Sometimes they arenāt free any more to move.
The āSaint Vitus danceā, also known as āwiper park sambaā is caused by the off-screen parking feature. Only the lack of it might cause concern.
Good luck
Jochen
75 XJ6L 4.2 auto (UK spec)
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I know it isnt the thing to do, but when I converted my GMC 6x6 from 6V to 12V, the recommendation was just to leave the 6V Starter Motor and give it 12Vā¦it sure did spin an lot quicker, (resulting in much easier engine starts)
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Iāll add my two cents here and relate what Iāve done.
I completely dismantled my wiper system and had to replace the ābrush plateā in the motor. At that time I found that my motor was a 29W item. I donāt believe I would go to something with less than half the wattage (14W).
I second everyoneās comments on re-greasing and lubing the spindles, one of mine had seized.
Because my 1985 S3 was in pieces when I hauled it home, I have no experience on how well various things operated before (wipers, windows, headlights, etc.). On advise from experts on J-F, I wired relays into the wiper harness. I donāt know yet if it helps, but most people say it will.
I have also put relays for high/low beams and wired them so that both sockets will have high beam and low beam.
I tried to get as much high current that usually runs through the ignition switch on to a relay. A separate fuse block wired through a relay is an additional Ignition Hot source for a few of my add-ons.
In my opinion, relays are your friend when running high current loads. The wiper upgrade required 4 relays, with the added bonus of removing the ground path away from the switch also. Hereās an early picture of where I put the relays and the wiring before making it a little prettier.
Dave
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Reminds me of my fathers Oldsmobile, Tonyā¦
It had two batteries in parallel - for 6V. With starting problems, cold and bad batteries, we connected the batteries in series - just for starting. At 6V the two batteries barely turned the engines - in series I bet we could have done 30 mph on the starter aloneā¦
First time, we forgot to close the doors - and blew all the inside bulbs, though we carefully turned off all other items. The starter is of course a tough customer, and can take it - since it is only used briefly and draws less current the higher the revs. Other items may be less forgivableā¦
frank
xj6 85 Sov Europe (UK/NZ)
**
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I have installed relays for the wipers, windows and headlights.
Their operation was hugely improved, I would say by 50%, all three have a modern feel now.
Later I installed a 120A Alternator that improved things even further but the most notable difference was at idle, the voltmeter never goes bellow 13 Volts, even with headlights, AC and aux and interior fans on, and the battery is always fully charged having plenty of juice to start the car in the morning.
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