2006 XK8.

Right tail light & license plate lights, fuse, #19,(in trunk fuse box) keeps blowing when lights turned on. Brake light and turn signal light work as they are on another fuse. Only tail light doesn't work

Disconnected the connector plug from the light assembly and still blew, so it's not the light assembly.

I've seen threads indicating that it could be the security and lock module, but according to my handbook, the left/right brake lights are controlled by it, and my right brake light works.

Having said that, I just had the security module replaced Wednesday and the "check rear light" notice came on, we think, the first time the lights were turned on.

Coincidence or something else? Maybe another fuse blown, (I've seen mention of that in similar threads)?

 

mbates50, Have you added the ground wire to the rear bulb assembly. There is a thread on how to do it somewhere. These cars have a small ground wire for all the rear and it's just not good enough.


Wayne

 

Wayne:

No, but the fuse blew when the rear bulb assembly was not hooked up.

Mark

 

Examine the plug that goes into the light assembly. The first connector on one end is the ground. If it has gotten hot from excess current draw it will distort and touch the light connector next to it shorting it to ground. You can push them back in place with a small screwdriver.
Make sure to research and add the extra ground. If you need help let me know and I can send you pictures of my plug and added ground.

 

Vern;

So this would cause the fuse to blow even when the connector plug was disconnected from the light assembly?

I'll look again, but I looked at them last night and they all looked straight as I recall. Maybe I need the extra ground so the pic would be helpful. Thanks.

Mark

 

Hi Mark
Open this PDF file - 2003 Jaguar X400 (XK) Electrical Guide - use Adobe PDF program to open the file, then go to page 75 (type 75 as the page number) that is the Exterior Rear Lights page (Fig 09.3)
use the following weblink to open the pdf file using your PDF program (File - Open):

Forum shortens the weblink reference - here is the full weblink (ignore leading xxx)
xxxhttps://www.jaguarforums.com/forum/attachments/xk8-xkr-x100-17/123375d1451210275-rear-tail-light-fuse-keeps-blowing-x1042004en.pdf

https://www.jaguarforums.com/forum/a...x1042004en.pdf

Look at the upper right side of the page - Trunk Fuse box - it shows the relay for rear lamp connected to fuse # 19, also the wiring from the trunk fuse box to the SCLM module, then to the rear lights. Looks like wire color code is R (Red wire) from fuse # 19.

check for any broken wire in the harness that is near the trunk hinge area.

 

SOLUTION! (I think)

Thanks Jim, for the PDF file.

Not knowing anything about electrical circuits, I looked at the diagram and pulled out the tail lamp relay to take a look. Nothing looked amiss, so I thought, what the hell and turned on the lights. The tail/license plate lights worked and no blown fuse with the relay out. Everything else works OK as well. (I beginning to think it has something to do with the newly installed SCLM, which is used)

So, I went to the Jag dealer to buy a new relay and got to talking with a service manager. He said that this should not be happening but that operating the car without it would pose no problem.

So the $64,000 question is: Can any damage to the electrical system happen, by not having the relay in the trunk fuse box?

Mark

 

Vern
You probably have a bad relay???
Look at this article on automotive fuses and relays - here is the weblink:

Automotive Power Centers, Fuses and Relays

Here is the full weblink - ignore leading xxx:

xxxhttp://www.aa1car.com/library/power_centers.htm

Part of the article explains what damage might happen, also how to check out if the relay is ok.

Jim Lombardi

 

Jim;

Almost there.

When my wife first drove the car today w/o the relay connected, no warning light came on and the right hand tail worked. On the way home, the check rear light notice appeared on dash, but tail light was still working.

I then replace the relay and everything works, no blown fuse, however the "check rear lights" warning is still illuminated.

Any clue as how to get this removed? Any way to reboot the security module as this part is what's activating the warning? Maybe disconnect the battery?

Thanks for all your help.

Mark

 

With the caveat that the wiring might have changed between the latest JTIS (which didn't change during 2001-4 in this respect) and 2006 models.

Looking at the wiring diagram, if you have any rear side or marker lamps lit with relay #R3 pulled then there are other gremlins at work as all the rear position lamps are driven via this relay and fuses #19 and #21.

The 'bulb fail' message could be either a fault in the replacement SLCM or a continuity problem in the LHS bulb circuit, wire colour-coded red/blue and including the connector, bulb and grounding.

Did you do nothing other than remove and replace relay #R3?

Mike

 

Mike;

This issue happened the first time the lights were turned on after the replacement of the SCLM. Since then, I've replace the tail light relay and both tail bulbs. Have checked for loose wires as much as I could and see not corrosion. The light assembly connector looks ok too.

ALL rear/side lights worked when the R3 was pulled.

The odd thing is the tail lights worked w/o the relay and the warning light stayed off for awhile. Now all works, but still warning light with new relay installed

Thanks

Mark

 

Try a hard reset by removing the negative battery cable, then put the negative battery cable on the battery positive post for 20 seconds. Not sure the hard reset will clear the warning, but it is worth trying.

Do you have the radio security code? You might need it after the hard reset (radio was not affected on our 2001 xj8). But your 2006 xk8, who knows??

Also look at the following forum posting (xj8) showing broken wires inside harness near rear hinge area (see post #4 in the posting):

https://www.jaguarforums.com/forum/x...issues-126542/

Jim Lombardi

 

Sorry to throw another variable in your quest, but normally, if you see something like "Cruise not available, Check rear bulbs", the culprit is the brake switch. It is a common failure. A bit of a pain to replace, but it can be sourced new or even repaired (a forum member has located the actual micro-switches and offers an exchange service). There are lots of posts about this on this forum.

Best of luck, keep us posted.

 

Thanks. Currently the "cruise" warning is not on, but I'll try putting it on cruise control and see what happens.

Thanks for the advice.

 

OK. I was simply going to disconnect. The radio will lose settings, but I'll get my wife to jot down the numbers.

QUESTION: Hard reset won't screw up the remote's settings to the SCLM will it?

Thanks for all your help in all this. Worst case, I'll take it back to the dealer and blame it on the SCLM they replaced

Once this is settled, I'll report back with the findings.

Mark

 

There is no need to mess with the cruise control. The actual switch is made with 2 separate micro-switches, opposite to one another (one is normally open and the other is normally closed), but controlled by the same cam mechanism, off of the brake pedal. If the control module sees that the switches are not opposite at all times, you get the error "Check rear Bulb, Cruise not available". This message goes away when the ignition is turned off.

 

As suggested by Jim, the wiring harness could be a culprit for the blown fuse #19. A few people have had issues with the boot plinth switch and number plate lamps, so it's not inconceivable that the lamp feed wire could be shorting out.

I cannot reconcile the 2004 wiring diagram to the symptoms you are experiencing: i.e lit rear bulbs and no R3. Something is different and it would need some first-line troubleshooting armed with a multimeter to resolve.

However, rewind the story and the issues begin with the replacement of the SLCM. Out of curiosity, what was the initial problem that motivated the dealer to change it, and do you have the original unit that was removed?

I don't recall having any issue with lost key fob programming after extended battery disconnects, but it appears to happen randomly in any case.

Good luck, the solution is out there
Mike

 

Mike: I'll re-check the wiring more in-depth this time. I replaced the relay and all is working except the the "check rear lights" warning is still on.

My battery leaked and ruined the SCLM and the carbon cannister. Both are house below the battery. Nice design.

 

Things are getting curiouser and curiouser. The "check rear lights" warning was not on when the car was started earlier, but came on later when my wife back out. I'll have to try and duplicate it and see if it's has to do with the brakes.

I had to clean out the entire trunk of dried battery acid and removed the negative cable, which did not affect the remote's programming, but lost the radio channels. So is this a sign that if I do a hard reset, I won't screw up the remote programming? I've been told that the programming has to be done electronically, not by standing on your head and flashing the lights three times while singing the Star Spangled Banner.

mark

 

Hi Mark
Here is a weblink to another thread on brake light switch replacement:
https://www.jaguarforums.com/forum/x...q-37758/page2/

Look at post #109 - forum member jsulliva sells rebuilt brake light switch for $25 and exchange - send a private message to him to get details. Look at the other posts in that thread for removal and installation instructions.

Jim Lombardi