So just went I thought I could actually enjoy my 2000 XK8 after having just purchased it 4 weeks ago, then had gearbox failure for the last 3 weeks (yes, new gearbox), and finally had it back on the road for the first time today.....

Well, we had a really bad rain storm this afternoon and I got caught on the expressway trying to make it home under extreme weather conditions, water floods and then got badly spashed by a left side passing truck! Well made it home alright, but just as I rolled in, got the "Battery Not Charging" failure message on the dash computer readout. I took it back out for about a mile, and the message would come up whenever I idled, but would temporarily go away when I was moving or accelerating. After about a mile, my steering got hard, gearbox failure popped up, airbag light on dash lit up and the Traction Control and ABS readout said it was also not working. The ASC light also came on. Obviously electrical or voltage failure.

So could this be that
A) Something shorted,
B) Something got disconnected,
C) Alternator Failure
D) Battery Failure.

It doesn't point to battery failure, but one of the other 3. Can anyone shed some light on this before I have to tow it back to my mechanic on Monday?? Thanks!!!!!

 

Check for water in your trunk. Behind the spare tire is the main distribution box...there could be water in it.

 

Thanks... I checked behind the tire where there's a thin box about 12 inches long attached to the rear and with wires protruding from left side. No water whatsoever in the area or trunk. Car doesn't leak whatsoever. Was quite dry. Therefore, don't think that's it.

Could something have come loose on or around the alternator?? Wires??

 

The alternator is located to the lower right side of the engine / engine bay. Therefore, it gets hit directly by any rising or splashing water. I can't get my head under the car to look up as the clearance is too small, or my head too big

The fuses seem OK (checked most of them, but only faintly scanned through luggage, engine bay (x2) and driver side fuse boxes.

I think my next step is a Johnny Walker Gold Label... That will definitely help right now!

 

Good day,

I had this happen to my Subaru... It would only charge the battery if the RPM's were up... If sitting too long, the battery would drain down to 10V and things would start to fail... Most of our electronics don't mind higher than 12V, but lower is a bad thing... I'd put a voltmeter on the battery terminals with it at idle... If you don't get over 12.8V, you need to swap out the alternator (or the internal voltage regulator)... Ahem... If you are at 12.8V or better, something else is amiss...

Good luck!!

Cheers!!!

 

The computer alerts with the "Battery Not Charging" when it senses a drop of voltage on the returning charge from the alternator to battery. I don't have a voltage meter handy, but I figure that's already a given (but assuming is definitely not the ans, I know...). I was just wondering if there's something amiss such as perhaps a disconnection due to the heavy splashing/flowing water while I was traveling through the storm. The car was perfectly fine till just after I was getting home, then the battery charge error came up and the car has been losing power since, so not sure how much longer the battery will last. Maybe will get me the 8 miles to my mechanic....

Don't understand why Jag would position the alternator so low or open underneath the engine if it can be shorted by water!?

 

You said the power steering also got hard - it sounds to me like the serpentine belt might be slipping.
Have you checked it and the tensioner ?

 

Man, you maybe right on... Wonder if all the water, etc, would have done something there? That should have been my first check... I just need a way to get under the darn car. I'll report back... (now that I think back, there was some strange squeeking at lower speeds, but just for a few seconds and faintly...).

BTW, if so, what is the proper method to tighten it?

 

The spring loaded belt tensioner should maintain the correct constant pressure on the belt. These cars have had a higher than normal belt tensioner failure rate due to bearings. The PS issue does say serpentine belt.

 

I thought about that too, but the PS issue only happened right after the water dousing and would be a result of the belt slipping... But I don't think that is still the issue (right?!)... The PS loss was just the brief moment after dousing?? Coincidentially, the dousing probably also shorted out the regulator which isn't usually affected by normal splashing water... Drowning might be a different result... I'm still pretty confident the dousing degraded the alt performance and swapping it will fix the issue... Oh, if you are having your mechanic do the work, he should be able to throw a meter on it to verify the output before replacing... If you will be turning the wrenches, have Autozone or the like to test the alt before getting the new one...

Good luck!!

Cheers!!

 

+1 on the comment about the PS going skynet on you... water will cause any serpentine belt to slip for a little while if it gets wet.

my previous vehicle had a gatorback belt on it, which lasted longer, but still was just as finicky as any other belt i had put on it.

my serp belt was so temperamental that i would regularly have to re-tighten it from season to season.

now for your voltage issue, i believe a charging test [WITH THE ALTERNATOR OFF OF THE VEHICLE] is in order. you may have fried the voltage regulator.

also, if you didn't catch the CAPS in the aforementioned sentence... do not take your car to autozone or wherever else to have them check the alternator while it is on the car. their tests have been known to fry other electronics in vehicles. take the alternator off and have them bench test it in the back.

did i mention not to have them test the alternator while it's on the car?

 

Excellent clarification on pulling the alt to have Autozone test it on the bench... I forget they can test it in the car and is not always the best idea, which is why I forget they can... Thanks!!

Cheers!!