I have been getting our 2004 XJ8 ready to pass safety inspection since it has been parked for 2 yrs.

I fixed the brake booster problem caused by leak in vac hose.
I fixed where the MAF sensor wire has been chewed through by rodents.

I cleared the codes caused by above items and they didn't come back. Took the car for a 1hr drive last night and it ran fine. Engine and trans was smooth as silk. Now I find that the car randomly opens all windows and sunroof when it is parked. I hear a clicking sound at the doors when it happens and the timing is completely random.

Also, the 3 tail lights turn on for no reason and stay on. They were on for a least 4hrs last night and off in the morning when I looked. Today we drove the car to get takeout for dinner and the car started randomly chirping as we were driving down the road. It sounds like a horn from a moped and is coming from the trunk area. Maybe the Rear Electronic Module making the noise but why? Any ideas where to start on this?

I see there is a command in the appendix called "All Rear Brake Lamp Command" but it doesn't say what triggers it.. Does anyone know?

I appreciate your input on this Ghostly problem!

Thanks,
Mike

 

"Any ideas where to start on this?"

Battery.

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The window thing could be a wayward, or unintentionally held down remote issue. (Double click and hold the unlock button.)

But you're multi-germlin.

If this is the old or an old battery, that's the usual suspect.

I'll put it this way, with vehicles having 25 or 30 modules, we no longer jump cars or charge with the battery connected. ( I get queasy even using my reasonably trusted smart maintainers.)

Ground plane goes along with this. Probably time to polish the binding posts for the ground points.

I have one above the battery on the upper wheel well. I have heard of one under the rear seat, passenger side. If the car wasn't under cover, water intrusion from the sunroof could show under the rear seat, as well.
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Just remember the ground lugs are all aluminum. Easy does it.

 

Thanks renovator,

I'll have the battery tested. It's not old and might still be under warranty. The car was kept on a smart battery tender for trickle charge while stored. It did go dead once when the GFCI breaker for the charger outlet was tripped. Could have been dead for a couple months. But since recharged, the car starts fine off the charger for a week or more.

It was happening when the remote was kept 50ft away in the house so that's not likely.

Car was parked under a well covered location so no signs of water penetration inside the trunk or the interior. Actually the exterior was kept very dry by the roof and side of storage.

Visually, inspecting the ground points behind the headlights were not appearing to be corroded but I read in a thread about those issues and was hoping I could avoid messing with them since they look so clean.

Seeing the pictures below, do you still think I should take apart and clean?

Here are a few pics of grounds in the trunk area:


Overall setup.


This is from the opposite side away from battery, near CD changer.

First ground point coming from battery.

 

We're going to be jumping between making sure the clean uninterrupted current can run and trying to make sure you have it.

Our ambient temps and local climate intensifies the troubles.

​​​​On these types of vehicles with our heat, even batteries sold as high-priced spread can have troubles like you're seeing at 3 and a half years. At four, you can count on it.
I'm not being facetious, I don't know how one really tests for what we need. A regular decent load tester will pull for 10 seconds and if it hangs at 11.7 volts will tell you what you already know. The car will start.

So, you'll see references to the battery being at rest with a voltage over 12 needed. 12.2 is popular.

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Looks like a silver car. Notice all the nuts are painted.

Aluminum oxides quickly. Aluminum oxide is good for many things. Electron transport is not one of them.

Take a 13mm or 1/2 inch wrench and gently pull one of those nuts... on a post with the smaller wires. If the unpainted flat face of the nut looks mottled grey that's the oxidized coating. Rub it on little piece of 320 > 400 grit laid flat. That bright shiny is what you need.

If you have a dremel with a wire or plastic brush bit, pull the eyelets off the post, and gently hit the threads. If puffs of white are floating around the battery compartment... there's your protective oxidation. That's what needs to get cleaned up.

Now we have the worst of both worlds. Lead oxide, too. It's a fine grey layer that developes on the battery posts. Not that obvious white acid cake, this stuff is incidious.

If you pull your battery terminals and the sides of the posts look like the tops, they need to be cleaned.

You have no idea how many alternators have been sold because of this layer. You can still get plumbers abrasive tape in 120 > 320 for polishing the posts. Or strips of sandpaper. Don't forget the insides of the clamps.

That abrasive on the white sandpapers in this range is aluminum oxide.

A long steady soak charge, and bright terminals may well mitigate most of this.

Be real easy on those ground posts. Just snug 'em up.

 

Thanks again for the suggestions. The battery is 5yo per Auto Zone records. It is rated at 900CCA but couldn't handle that full load but did test good at 750CCA. Not surprising for a 5yo battery. Car cranks very fast and starts easily.

The car is charcoal gray and all the nuts have body color paint on them but I see what you mean about the copper to aluminum mating surfaces having the oxide because of dissimilar materials. This is the same problem caused by using aluminum wiring in a house and joining it with copper/brass fittings at the outlets and such. I will open a few up and inspect. I have all the tools needed to clean.

Does you car have the HID headlights or the standard H7 bulbs? Mine are standard H7 and I have a strange headlight adjustment issue. I only have one headlight adjustment nut for each side. When I adjust it for the lowbeams to shine correctly, the highbeams are shining at the treetops.... Way to high and visa-versa. The X350 workshop manual shows a picture with 2 adj screws on each side but I only have 1. Have you any experience with adjusting headlights or possibly I will have to start another thread. I'm dreading I will have to remove bumper cover just to adjust headlights. I'm tempted to try some LED replacement bulbs in it but afraid I might cause more electrical issues. I put some in my 06 F150 and they are great.

 

"This is the same problem caused by using aluminum wiring in a house and joining it with copper/brass fittings at the outlets and such."

Mike, you have no idea how you brought this home. Thank you.

I spend plenty of time explaining galvanic issues on various projects... But I never linked the terminal end corrections on aluminum wiring, to the same oxidation troubles. To wit: as I was cleaning my stuff up. I was rattling around the idea of a protective salve for these connects. Plumbers grease is all silicone, no good. Maybe nickel based never sieze... hmmm.

Wait, it's in the parachute bag with the electrical connectors... ox-guard. Duh.

You may be onto something here. Mr. Mike.

(Yeah that's also why the nuts are nicely painted.)
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You get my point, you're dealing with 12v or 5v tolerance stacking. A new battery will probably blow through the troubles, but if you have the time, cleaning up any weak spots just helps.

I don't see the rear ground point I was thinking about in your pix. Mine is under the passenger side panel in the trunk. DonB has pointed out about one under the rear seat, that's used by the ASM. I don't have that one.

The points are laid out in the : 2005 Electrical Guide . Hope that's close.
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I'm in the same sit getting through the inspection after two years. I've had mine a few months and that time was eaten up by weirdo suspension issues and putting a laptop in service for the SDD, traveling, etc.

So, I'm just getting around to pleasantries like the lighting color temperatures and bulb configs.

I do have two hex adjusters on each headlight assembly. The high beams look like halogen bulbs from the outside. The low beam / drl are behind projector covers. I think I read about HID's somewhere, maybe there are ballasts under my assemblies. ( I need to drop the bumper cover anyway, the paint is either faded or a mismatch, there's curb rash on the bottom, etc. But I have another bumper cover in front of it . So it won't be this week.)

Keep in mind the '08's were at least a facelift, so there will be differences.

Actually, I think my Nokya's for the fogs showed yesterday. Going to throw-back traditional on those with yellow fog H11's. The other's will be in that ice white/blue range. What looks like aluminum trim around the fogs, needs to be refinished, the lens' have weird oxidation patterns and will try a sand and polish. Fortunately, except for paint chips, that's all the exterior cosmetic.

I did swap out the parking light 194's with bright LED's, I haven't really done enough to create any canbus issues, if they exist. These may just be old enough that they won't notice the swaps. (I've got a bmw I'm dealing with, that's schizophrenic about license plate light bulbs of all things.)

 

I passed inspection yesterday and now I can get the car registered again. Funny thing is the car was completely silent yesterday while driven ~50 miles until the mechanic pulled it in the inspection bay and turned the key on with the diagnostic monitor connected. Then the module in the trunk started chirping... almost like say "get away from me, I don't know you". They told me they thought I put a proximity alarm on it

I looked at Ox-guard and see it's conductivity is caused by fine shavings of Zinc in the solution. I'm kind of up in the air about putting any kind of solution behind the metal and copper in the trunk grounds that will carry high current..... I thought maybe a Zinc star washer in there would bridge the metals well and then coat the whole thing with either 100% silicone or paint or ?? I read what electricians use for the dissimilar metal issue and there are a few small expensive connectors for outlets & switches but for high current lines it is best to pull out the aluminum wire.

Aluminum house wiring was introduced in the mid 60's and used until early 70's. By the 80's they knew about the problems they created. You would think Jaguar/Ford would have been smart enough to learn from the mistakes and not build cars this way even 20-30 years later!!

I'll start a new thread asking about halogen headlight adjustment w just one screw available and about switching to LED headlights and see where that goes.

 

Zinc's the classic sacrificial anode.

I think I'd rather it be in solution, than as a potentially dissolving spacer in the connection.
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I'm with Ford on this one.

Their commitment to this all aluminum unibody is getting awful close to a lightweight monocoque. Not by definition, but by theory. The stiffness is pretty impressive.

It's commendable. Ridiculously challenging execution, while evoking the handwork of the older-now E types.

​​​​​So what were looking at with the matrix of ground bonding points, is a more rigorous attempt to prevent the ground issues that we've always fought. The engine and alternator were isolated by mounts and the battery box and lights were on the other side of the ground straps. We deal with it on lots of vehicles as they age.

It'll be fine.