Hey guys, I recently purchased a 2004 xj8 and love it. I've been fixing the little issues as I go but I'm a bit stumped on this one. When I use the right turn signal the left running lamp/brake lamp will blink and dim down the power to the right turn circuit. When brakes are applied it will also make the center high mount brake lamp blink as well. It seems as though I have a grounding issue. All fuses check okay and both tail lamp housing connector terminals look good too. Any help is appreciated. Thanks!

 

Ah, see ...

https://www.jaguarforums.com/forum/x...signal-175509/

that may be helpful ?

 

Yes, thank you, I've reviewed that post, was there a conclusion? The description of location for g24 is confusing. Is it located in the kick panel on the passenger side? I've checked the grounds in the spare tire area and by the REM module. All look good.

 

Alright, I just learned the trunk is aka "boot" so the ground should be near the battery behind the liner?

 

Hi CpXj8,

Welcome to the Jaguar Forums. It's great to have you with us.

Regarding the grounds, you cannot tell if they have a problem by looking at them. The threaded studs, nuts and harness ring or eyelet terminals are all made of aluminum and a thin layer of aluminum oxide forms on them and resists or interrupts the flow of current. You need to remove the nut and terminals, clean them thoroughly with a small brass-bristle brush and zero-residue electrical contact cleaner spray, allow the parts to dry, then carefully reassemble. The torque specification for the nuts is just 6.5 ft. lbs., which is barely more than hand tight, so just make them "snug." Several owners have discovered how easy it is to snap a threaded stud off the body by overtightening the nut.

See this post on cleaning grounds:

Grounds/Earths Near Headlamps

Regarding ground locations, here's the rear end section of the diagram from the Electrical Guide:



You can download the Electrical Guide at the link below courtesy of our member Gus and his website, jagrepair.com:

2004 XJ X350 Electrical Guide

In the meantime, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Thank you very much for the reply Don! Lots of great info there. My update for tonight was I cleaned all trunk grounds paying careful attention to g24. I did clean it using the procedure you pointed me to. Unfortunately, I still have the same issue. I checked pin out of both tail lights and found them to be identical so I swapped taillight assemblies and the problem remains the same. So, I've eliminated the tail lamp housings and the ground they share (G24) looking at the schematic, I'm not seeing much other causes other than the rear module. Does anyone have any other tips or checks to make? Again, thank you in advance!!

 

There has to be some electrical guru's or someone that's had this issue that can help me out?

 

Here's my update, I load tested every ground from the REM module, all test okay lighting a halogen bulb while touching battery positive. At that point, I condemned the module. I found a donor car with the same REM part number and plugged it in. I have absolutely no change in symptoms. I also noticed that other bulbs in the back are ever so lightly illuminating. Looking at the schematic, I cannot see how the issue couldn't be isolated to the REM /REM grounds. I would really appreciate another set of eyes on the schematic. Someone help?

 

Ok from what you have described it's possible that the fault is with the fuse box in the boot or trunk. This has a circuit board on its base which somewhere some diodes seem to fail and cause these odd interactions between the rear lights. See if you can get yourself a used fuse box off eBay and give it a go, dead easy to change over as it's just a series of plugs.

 

Just thinking out loud. The REM switches the grounds to activate the lamps. The power for the lamps comes from the Rear Power Distribution Fuse Box (RPDFB). If the left brake lamp is not connected to ground, it should not illuminate, so that makes me wonder if its ground wire to the REM may be shorted to the ground wire for the right turn signal lamp. You could test this easily enough with an ohmmeter at the appropriate pins of the electrical connectors for the lamps and REM to see if those wires are shorted together.

Please keep us informed!

Cheers,

Don

 

Thanks for the reply! I'd like to do a bit more testing before throwing more money at it.

Thanks for the reply Don! I will definitely do that, I need to find some more time to dig into this. With a 2 week old newborn at home, the wife & I have been busy! I will keep you guys posted and I really appreciate the time you guys have taken to reply.
-Cole

 

Some people have had problems with the stalk itself apparantly the wires are realley

crammed in there-I am not saying that is

your problem but it is really easy to replace.

Another found that replacing the fuse solved a problem.

You may have a DTC so scan for codes if you able.

Google this or similar "jaguar x350 indicator stalk fault" for

possible ideas.

 

Many have reported the boot fuse box has caused many of these problems. Many have swapped it out and cured many lighting issues. If you have a donor car I would try swapping it out. The circuit board on the rear fuse panel has not been know to be the most reliable. Swap from the donor, check results. Will cost you nothing. If not swap it back. The bad circuit board may not show up on basic ground checks. I also thought that some have mentioned a non-repairable relay built into the board failing.
Mark

 

Don't brease past Meirion1s post. Given the logic of "simple things first" the signal stalk should be eleminated early on.

 

Here is the answer guys, your recommendations were correct. Upon my testing last night, I ran many checks. Removing the pin 4 (turn signal ground from REM) from the right tail lamp and connecting a test lamp to batt +, the turn lamp operates as it should, with out feeding any other rear lamps. At that point, I knew I was not dealing with a grounding issue. I then reinstalled the pin 4 and removed pin 7 (main power to the circuit) and load tested that to ground. Tested okay. Checked c98-10 (output of rear fuse block) still tested okay. I then applied clean voltage straight from the battery to pin 7 of the tail lamp housing. Everything works as it should. The short exists in the fuse block... ISSUE RESOLVED! Time to either run a new fused circuit or locate a used fuse block.

Thanks everyone, for the help along the way, especially to Don for hooking me up with the electrical manual!

One final question, Does anyone have a source for tail lamp housing connectors or individual terminals for them? They are stamped Ford but the numbers from the connector give me nothing and searches in the forum or Google yield me little information.

 

Post pics of what you need -might help.

 

Thanks for the info. I have the opposite problem. I turn on the driver side (US Car) turn signal and the passenger side or right tail light blinks in sync with the turn signal. I have no dimming problem like CpXj8 has.

Do I still check G24 or go to G25?

 

I would check the ground, if that's okay, which I'm sure it it, replace the trunk fuse block. Good luck!

 

Thanks very much for this info. The same problem happened to my car today...tomorrow I'll get to work on it!