OK, ... I've had a few little electrical sniggles here and there for the passed year and a half, but now they've gone into the bizzare zone. Typically that means a ground fault of some type, but I'll be damned if I can tie these together.

The weirdest incident occurred recently when I turned my fan on one morning (fan only - no a/c). Simultaneously I got a transmission fault, the wipers went across the windshield, the steering wheel lowered (in manual mode!), and the windows deprogrammed themselves.

Having my windows lose their program is becoming almost a daily event, and yesterday my trip computer zeroed itself after a fuel stop. For quite some time now all the lights in the cockpit will sort of wink/blink at me (with or without the headlights on). They don't actually go out though - they kinda dim and brighten quickly. The headlights simultaneously do it too, but I can't tell if they're actually dimming or just momentarily dipping down toward the ground.

Transmission faults have started popping-up at a concerning rate. If it was a normal tranny, I'd just figure it to be a tranny problem, but being an electronic tranny, who knows what else could cause these things!

Anyway, back to original question: Can anyone tie these anomalies to a particular ground point?

Does anyone have a map of all the ground points (and how to get to them)?

GREMLINS!!!!!!

 

Hi scardini1,

Window memory loss almost always points to a dying battery or one in a low charge state. The car will often start OK. Wacky, inexplicable error messages can also have the same cause. If you haven't done already, get the battery load tested. How old is it? Most times the month and year are stamped on one of the terminals.

Second thought would be a charging circuit problem (alternator). I've just replaced mine; loads of errors on the in-dash display and pulsing lights. If you have a code reader, check for code 1793.

HTH, Mike

 

The battery "should" be OK. Replaced less than two years ago.

But the alternator, .... hmmmm. It's got 150K miles on it. That's an interesting idea. I'll have it checked.

Thanks Mike!

 

Ground connections and loose cables are always a problem. I would check the battery cable ends. They may look ok but moving them around you might find the conductors broken where it is crimped. Anything offering resistance and lowering voltage is going to make the cat grumpy. A problem I had before was a loose nut on the power wire from the alternator. A thorough check of connections will probably resolve the problem.

 

Jim,
I'm no expert (and there are many here who are) but I think it would be worth 10 minutes or so with a simple voltmeter to check whether all the volts in the battery are getting as far as the engine compartment. May be different on LHD cars, and later cars may be different to my 1997, but with the engine running, check you have about 14 volts across the battery terminals. Then, with the negative probe connected to a GOOD earth in the engine compartment, measure voltage at the main terminal on the fuse box :

and also at the connector in the "false bulkhead" on the rear right (on my RHD car it's where the brake servo is located. Photos show both sides of this stud which is covered by a rubber cap. If you have, or don't have, a good 14 volts or so at both these places it may help to narrow things down a bit.
Cheers,
David.

 

Excellent advice from David.
It is something I do once a year, check/clean and tighten all ground points.

So far, I have never had a problem with any of my cars. I would highly recommend doing it as part of your own preventative maintenance programme.

You may find a lot of your gremlins suddenly disappear.

Jim

 

P.S. Jim is 100% correct about ground points but ............. to avoid any confusion and a potentially VERY expensive bang, the two places in my photos are BATTERY POSITIVE.

 

Excellent stuff (as always).
David: The pics are a big help - Thanks!
Vern: Was the loose alternator nut actually at the alternator, or the other end?
Jimbov: Do you have a list of the ground points you check?

Death to Gremlins!!! B-)

 

Hi Jim,
The attached chart shows where all the ground points are. The main ones to check are in the trunk and engine bay and any you can find underneath.

Don't forget to do the live terminals at the same time, with the battery disconnected of course. Eventually you will find you have a different animal on your hands.

Hope this helps you out,

Jim

 

OMG! How many of these grounds do you check?!

This is going to take a weekend (if I'm lucky) for sure. Are there any more "local" diagrams that show the vertical locations (i.e., under car vs. inside car)?

I have a maintenancemanual as well on a different computer. I'll check there as well.

THANKS Jim!!!

 

Attached you will find a link to a wiring diagram for your car.

Link http://www.jagrepair.com/images/Auto.../jagxk2003.pdf

When reading your electrical problem several things came to mind first get a load check on your battery and electrical system at AutoZone, Advanced and or Sears they have the equipment to check battery and charging system properly.

As for you checking your grounding connections remember that the ground lead from the battery is attached to the body of your car in the trunk. In doing this your entire body acts as a ground for the cars operating systems except for the engine and that ground connection is from the body of the to the lower transmission bolt on the right side of the transmission. Remember that the body is the ground and ALL applications that need a direct connection to a ground is connected to it and is indicated on the grounding illustration on the wiring diagram.

As for the poltergeist the winking and blinking could be a poor connection or just low voltage. Get the electrical charging system and the battery checked first then check the connection in the trunk and then check the one from the body to the transmission.

 

Thanks Gus! I'm sure this will be a big help. How much carpet am I going to be pulling? (Cringe).

 

None! All connections are either under the trunk, hood or ouner the car.

 

IN MY EXPERIENCE ALL MY OLDER CARS HAVE THE NEG. CABLE FROM THE BATTERY DIRECTLY CONNECTED TO THE ENGINE BLOCK. (Battery in front)

I wonder if my xk8 would benefit if I ran a heavy 2ga cable from the neg. battery ground point forward under the car to the engine block. It would only take an hour to do. There is even an unused grommeted hole in the truck to use. I determined that is where the sand and dirt is entering the truck.

 

Thanks Gus that was great news about accessing the ground points. Last night I decided to look for those in the engine bay. Of the 6 or 8 that might be there I found ONE! And it wasn't even at one those locations on the diagram. It was on the right (starboard) side on the fender wall next to the radiator and just in front of the A/C accumulator. This is going to be fun! (groan).

 

Have you had your battery checked yet? Before you spend a lot of time trying to hunt down a fault, it seems from your symptoms you may have nothing more than a weak battery.

 

John,

Honestly, unless something has gone very wrong in the stock arrangement, it isn't going to matter. The chassis itself is an awfully big conductor and is strapped to ground right at the battery. At many points, in many systems, we count on the chassis being at true ground ... 0.00 volts relative to the negative battery terminal.

Also, anywhere we're suspicious of a ground connection, we can test for it with a good digital voltmeter. So for the engine block ... connect a DVM set to the lowest scale between the block and the neg. battery terminal. Watch the meter under even the most extreme conditions, i.e. while cranking the starter. If no voltage appears, the grounding of the block is sound, and a direct cable to it would not matter.

 

Thank White. Agreed - easy stuff first. I'm having checked today.

 

Just my 2c but I notice the XK has 4 fuse boxes all supplied with a big fat +ve cable. I'd expect each one has a big fat earth point too. Which fusebox feeds everything that goes mad? Suggest you look closely at the nearest earthpoint to that fusebox.

 

Yup..... Check the easy stuff first.

I had the car outside an AdvanceAuto for a battery & alternator check, and was checking all the grounds I could in the battery area. They were all good. Then I knocked the hot lead on the battery by mistake - - - AND IT MOVED! Nuts. So I cleaned up the connection, reinstalled and had the checks done. Everything looks OK. Maybe that was the root of my problems. We'll see. Looks like the last mechanic to work on the car didn't "quite" finish the job. (groan)