Found jag in the morning with a dead battery, after driving it the night before.
Charge the battery for a few hours.
Started fine, drove it around the block then turned it off and it continued to run. Dash lights went dark, RPM to zero but engine still running.
After a few attempt it did turn off but air bag light stayed on the 'P' in the shifter was lit.
Lights turned on and off a few times during the next 10 minutes.
The steering wheel went thought a couple of up and down motions (electric adjustment type).
I disconnected the battery for now, i did find water in the trunk, don't think that has anything to do with it. Although there are some fuses and electronics back there.
I thinking ignition switch.
Any thoughts.
I read old previous of " engine won't turn off" but never said the actual problem except the mechanic said a 'drained battery'.

 

Before going any further, I would suggest charging the battery for more than "a few hours". An insufficiently charged battery can cause all sorts of gremlins to appear in our S-types. You may well have an issue with the ignition switch, but any electrical troubleshooting always beings with a properly charged battery. If the battery is more than a couple of years old, load testing would also be a good idea. Most auto parts stores will do this free of charge.

Water is the trunk is never a good thing, so get the trunk thoroughly dried out and find the source of the leak, which is going to be typically either the trunk seal or the seals around the trail lamp assemblies.

 

The charger was acting funny yesterday when I was charging the battery while hook to the car. Meaning charger's needle spiked then dropped a few times while charging at 6 amps but when I set to 2 amps it was ok. Put the charger on again today and disconnected the ground from the battery and is now charging at 6 amps fine.

 

Interesting problem. I also think it's your ignition switch. But as previously suggested, fully charge that poor battery. You may end up chasing your tail if troubleshooting with a battery that is only partially charged.

Back to your ignition switch. Wiring diagrams here:

http://www.jagrepair.com/images/Auto...01999.25en.pdf


For the engine to continue running, it must have power to the fuel injectors, ignition coils, and PCM. No idea about other items, but those are the three biggies. Look at figure 03.3 for those three circuits. Power to these three take you back to figure 01.6 and the two Powertrain Control Relays in the middle of the diagram. The upper relay in the diagram sends power to the PCM and the injectors. The lower relay sends power to the ignition coils. Both relays need to be energized for the engine to run. It would be highly unlikely for two relays to stick closed at the same time. However, both relays are controlled simultaneously (in parallel) by the ignition switch.

Still on figure 01.6, follow the single control circuit for both relays to the upper left corner of that diagram. The #10 inside a circle leads you to figure 01.4, and that circuit passes through fuse F4 in the Primary Junction Box. With the fault active (key switched off), pull that fuse. If the engine stops, then we know power was somehow being sent to energize those two relays via this circuit. The most likely culprit for that is a bad ignition switch. There's a remote possibility of power getting there via some other means, such as two wires rubbing together, so we can dig a little deeper for that if interested. But first, please try pulling fuse F4 at the Primary Junction Box and see what happens. If you're not familiar with this fuse panel, it's inside the cabin, just outboard of the US passenger's feet, near the door hinge area.

 

Thanks great stuff. The pdf doesn't show diagrams only words, that's ok I will follow your lead. I will let the car charge up over night and see what happens. I it doesn't turn off I will pull fuse #4 in the passenger compartment fuse box. Will let you know what happens.

 

There's 149 pages in that PDF, lots of diagrams.

 

Scroll way down to see the diagrams themselves. For reasons unknown, Jag put the text pages first, followed by the diagrams.

I suspect a faulty ignition switch is what killed your battery originally. With a partial failure, some circuits may have remained energized even though the engine turned off normally. Then the next day, the switch stopped leasing the farm, and instead exercised the option to buy. That's when the engine wouldn't turn off.

 

Charged the battery overnight, took it in to have it check, A ok.
Battery back in the car, starts fine and turns off fine.
Is there anyway to determine if the car is drawing power when turned off?

 

Sounds very familiar to this problem ==>> https://www.jaguarforums.com/forum/s...rouble-214690/

 

It sure does. I saw that wire in the trunk. As I mention the trunk was wet and the wire he mentions was in the water. I will check and pull #12 fuse.
Thanks so much for the info.

 

Ooh, that makes a lot of sense.

If the ignition switch had failed, I was concerned that it seems to have healed itself after the battery was tested and recharged. There are no computers involved in energizing those two powertrain control relays. It's just straight DC from the battery, through the ignition switch, with a fixed ground on the other side of the actuating coil. Even if every onboard computer module was misbehaving, that wouldn't affect the control of those two relays.

Meanwhile, if the transit relay harness was at fault, as you've suggested, it leads to the last piece of the puzzle: Why did everything suddenly work normally? When the battery was removed for testing and charging, I bet that little harness got bumped. Maybe that was just enough for the damaged wires to stop touching. Fingers crossed...

 

if youre reffering to the white battery isolation connector that is not plugged into anything after the transit device is removed from the battery for pdi then yes that one. Wet with corrosion that connects the pins or pinched when a battery is installed will backfeed and keep the car running with the key out. Cut the wiring back a few inches as needed and tape up to the harness

 

Here you go:

https://www.jaguarforums.com/forum/s...-drain-123535/


I'd suggest running through that test even if everything seems to be working now. The fault may still be present, just not as bad as before.

 

I will check the power draw later today, voltage meter not working I think the fuse is bad.
I did check the transit wire in the trunk and it is hot so I pulled the fuse.
This wire was wet when the problem started.

 

This wire that was hot: Do you mean it had electrical power on it? Or do you mean it was physically warm? Normally I'd think you meant just the simple presence of power, but you had also mentioned your voltmeter was not working. Call me confused...

For the water in the trunk, check out this thread for more info:

https://www.jaguarforums.com/forum/s...ng-trunk-7798/


Specifically, see post #35 for Gus' experience with water leaking at the tail lights.

See post #42 for my experience with the trunk seal. I replaced that and didn't touch anything else. Voila, no more leaks.

The tail lights and the trunk seal appear to be the two main causes.

 

Yes wire had electrical power to it. I tested it with my test light. My volt meter is still not working even after replacing the fuse. I had to order another meter which will take a few days to arrive. I will let you know what I find out on the voltage drain test.