Nice title huh? Well, that is exactly what is going on. I am driving a long and....BAM! Every light and whistle goes off. The first time It did this I turned it off (thinking it would reset) and of course it would not restart. I had to get a jump at night, with no working lights, at a stoplight, in the middle of the road! Good thing the battery is in the trunk. When it happens I can limp home, take off the negative terminal, wait, reconnect, then everything is fine until it happens again. It happened a few times three months ago then it did not happen again until now. Please help me pinpoint it.

Here is exactly what is happening. I am using the car as normal then a red oval dash light comes on, then the abs traction light comes on and then the message center usually displays some random message like "driver door open." As soon as that happens nothing works correctly. Steering is heavy, idle is high, lights do not work, windows work some of the time, radio and ac do not work. If it is put into park it locks and will not go into any other gear (it is automatic). Also, when this is happening the traction control is on constantly, so you have to punch it to go anywhere. LOL

Any Ideas?

Ok, With the car running, I took off the negative battery terminal and the car died immediately. Does this indicate a bad alternator? That does not make sense. The battery is still fully charged and has never gave me any trouble starting it. Also, the alternator belt is good and tight. Will an alternator fail for a short period then work normally again? Will the engine charge the battery when the alternator is not working? I would test the alternator but as far as I can tell there is no way to get to the positive terminal on it.

 

I would think crazy computer would be tied to power systems, and one time I had some odd behavior - vanity lights would not go out, alarm would not arm...but in no way as much as yours is. I reset the system by removing the negative cable and all was good. It looks like your resets are not working. So many modules acting up is very weird.

I would seriously look at the power and recharging systems.

 

Hasn't this happened on S types before. I remember reading some posts with wierd electrical problems and multiple CEL codes thrown, all from a throttle body needing relacement. This would usually happen during a downpour though. Correct me if I'm remembering incorrectly.

EDIT: here's the thread...

https://www.jaguarforums.com/forum/s...ad.php?t=26975

 

good cross-reference peniole.

UCMYPOST, try to avoid double-posting in the General area AND the model section, its hard to keep track of your replies. In this case, the XK8/R section would have been just fine.

 

Second that H20 but he is not the only one. There is an XJS that is hard to keep track of.

UCMY do not disconnect neg batt cable with car running this can really screw things up (with your bank manager).

Apart from all the other advice from both sections.

With the car switched OFF disconnect the Positive Batt lead from the battery and then touch this lead to the Negative Batt terminal. This can cause a hard reset to occur.

Sorry can't help more, don't know about the XK's

 

Hi UC...wow, some problems you're experiencing there bud

I don't know if its relevant / helpful or not, but I remember a discussion albeit in the X section about engine management issues and doing a " hard reset"...this involved taking out a certain fuse for around 30 secs or so and then replacing.....seemingly this caused the ECU to hard reset.
It was related to fuel issues and the changeover from regular to premium fuel to get the most out of the bhp available and to get the car to relearn.

May be helpful / may not - just at hought

 

I took it for a spin today and after everything went ape sh*t again I noticed the Volt gauge was laying all the way to the right which is below 9 volts. Now the question is, does that gauge measure the battery voltage or the alternator? Until I find out I will be on the edge of my seat watching my email because I already ordered an alternator. Any advice or links for installing it?

 

Help!

 

Thanks in advance

 

Ok, I started it up and watched the Volt guage on the dash. It read around 11 and 10 volts. (not good) When I turned on the ac it went down to 9 or so then jumped back up when I turned it off.

What does that dash voltage gauge measure? Does it measure the alternator or the battery? Should I go ahead and swap the alternator myself. To be safe should I get a voltmeter to test it before I yank it.

 

Test your battery voltage with a meter BEFORE you start the car after an overnight stop. Expect just over 12v, under 12v and that battery is not charged enough. (Could be the alternator, could be a drain when your switched off).
Start the car and test the voltage again at idle (no other electrical loads). Expect around 13 to 14.5v, lower and the battery isn't getting enough, higher and the battery's being cooked.
Turn the headlamps on and some more load, say the rear screen heater, watch the lights closely while someone raises the revs a little - they should get a little brighter, it's a crude test for a functioning alternator.
Tell us your readings.
Crazy electrical events are common for a failing battery (yes, even if it starts the car).

 

Hey guys (I assume)

Thanks for all the help.

I swapped alternators. I can help anyone that needs to do the same. Everything is back to normal. I had so much fun tearing it up with the new found power, that I lost traction at 'highway' speeds and the fail safe kicked on. I was relieved. LOL Other than that everything works great.