Been driving it the last few days and all seems back to normal. But thanks for the hints. I have always carried a spare relay and if/when it happens again, I'll refer back. But will have to check those grounds in Bob's TSB as for the whole 15 years I've had this car, about one in a hundred times that I start the motor, the windshield wiper will swipe once and back. It doesn't hurt anything so I've never tried to diagnose it, rather I've just chocked up to a Jaguar "quirk". Never would have thought that would have been in a TSB.

 

So did it get back to normal on its own, or did you do something that resolved the issue?

 

When I unlocked the trunk with the key, it was completely dead. It came back to life as I was removing the floor of the trunk to access the battery area. The only thing I can imagine that happened that might have "caused" its spontaneous resurrection is that the trunk flooring had to have touched the battery positive cable while I was jostling it out, tho when I inspected the cables, I found nothing loose or corroded or anything wrong at all. I proceeded to test the battery condition, check the charge voltage, take all the terminals loose and put them back and check a bunch of the stuff y'all posted without finding anything obviously wrong. I didn't "repair" anything, but I "touched" a lot of stuff. The only thing I "cleaned" that really needed cleaning was the engine ground strap, but the car was already back alive and well before I got it on the lift to access that. There's just no telling what brought it back. I've been driving it for days now, it seems perfectly stable as if nothing was ever wrong. <touch wood> That's what I hate about electrical problems, true ghosts in the wires kind of thing.

The idea about a relay going bad seems to make the most sense tho. I've always carried a spare relay and when it happens again, I'll swap relays around one at a time to see which one, if any, brings it back to life next time (or have it towed back home). But there's no point in trying to "diagnose" while everything is working perfectly. I just have to drive it until it acts up again. It may be all Denso components, but the Prince of Darkness has paid a visit anyway.

 

If it ain't the relay (maybe loose), you might have a bad battery post. Had a Ford (long time ago) where the post was loose INSIDE the battery case -- Sears replaced it with a new one.

 

As I explain in the ground lanyard rebuild link in Post #11, I tell of this identical scenario. That mesh lanyard corrodes, you can't see it but they do and need replaced...highly suggest reviewing that.

 

I've seen that on a bike. I'd put it down to an idiot massively overtightening the bolt & bending the casing as they did it. Probably happens due to random faults too though, it's just everything was overtightened till it stripped then backed off half a turn on that bike.

 

Unlikely I think on two different batteries tho as these symptoms appeared before about maybe six years ago, never figured it out then either, just returned to normal on its own, and the battery was replaced two years ago with a different brand.

But oh well, the quirkyness is part of what makes these cars so endearing I guess. I never hear anybody name their Accord or Camry. They're just machines that work. Jaguars are more human, as they age, waking up in the morning with little aches and pains their doctor can't explain and so they just learn to live with it. That's why some owners give their Jaguars names. I've never named my cars but my brother christened my XJ8 Annabelle after the old Midas Muffler commercial from the 60s. Old man McCreedy brings in his Model A for the umpteenth lifetime free replacement muffler, the young mechanic suggests its time he got a new car and he replies "Oh, I could never sell Annabelle!". I'm beginning to think she's a living thing and that the name fits. (And I'm starting to look like Mr McCreedy.)

 

After reviewing this thread: I think Highhorse had it right (#11). Corroded cable.

Roger, they are alive, at least in our soul: Bandaid looked lovely when I rinsed the pollen off her this morning.

Maybe when you get to a certain age you fear being thrown away for a younger beauty, too. Therein the rub! As I toy with dumping her, she is running better and better . . .