XJ XJ8 / XJR ( X308 ) 1997 - 2003

X308 XJR 1998...Real brain teaser!

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Old Sep 24, 2025 | 04:14 PM
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Default X308 XJR 1998...Real brain teaser!

Hi all. I'm in need of the deep minds of the Jag experts on here, and I'm not joking.....
I've taken on an abandoned project, a 1998 x308 XJR with 90k on the clock.

It needs ALOT of welding, which is fine as im a fabrication welder.
basically everything from the doors down needs work so patching isn't an option, the floor pan has gone as have the rear suspension mounts, so it's a hand full.! Having driven it into my garage and removed the battery, stripped the doors, boot, lights and bonnet off for ease of access and in prep for the respray (I've only a small garage) I accidentally cut a few wires whilst chopping out the rot in the drivers side rear foot well.(RHD). I've repaired the damaged (6 wires) but after the welding and reconnecting the battery the car is dead. It won't prime the fuel pumps or crank.
the dash shows Gear box, failsafe and incorrect part fitted.!
I've tested the wires that were damaged and the repairs are good as are every fuse and relay on the whole car!... I'm getting 14 and 23 faults on the climate control that wont clear.
My icarsoft reader has thrown up the codes
U1041 B2368 U2012.
And U1135 Po100 P20e2.
But says it has a communication error so won't clear them.
The battery is new

Theres a pair of two wires around the fuel tank that i dont know if they should be connected, pink and gray on one then blue and red.
Therse also a pair of black and black and gray in the drivers foot well that i dont know where the hell are from??
Can anyone, well, anyone that actually knows what they're talking about give me any advice as to where to start to look ?.
as as far as i can tell any damage that i caused ive repaired and im guessing that the car would start even if the doors wernt connected??
the only thing I can think is that one of the B pillar alarm sensors was damaged at some point so ive ordered a replacment....
could this be the issue?
The key turns fine but all I get is the relay behind the drivers seat clicking....and a dash full of faults that wernt there before i started to save her.
I did say it was a head scratcher!..so, can the guys that like a cunumdem please reply, and the guys that don't really know what they're talking about please keep quite!
if the issue is solved through this forum im willing to give a donation to the air ambulance or one of your chosing.
thanks all
Howard.
..
can anyone give me a place to start looking?
if needed can anyone recommend an auto electrician around the Bradford area of west Yorkshire but it pains me to use so-called pros as iv had my wallet empied with no result before!.

Thanks all.


 
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Old Sep 24, 2025 | 08:38 PM
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> The key turns fine but all I get is the relay behind the drivers seat clicking....
Have you checked the most obvious possible fault? ...flat battery!? Note: Even a battery, which measures - let's say - 12.3V before ignition ON might not be up for the job...
I recommend battery charger CTEK 10A or 15A.
And as you have cut thru wires: Did you check the fuses?
 
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Old Sep 24, 2025 | 10:14 PM
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Search “electrical guide” on the forum and you’ll find the factory diagrams with wire colors. Pictures would help.
Is the car too far gone? I’ve seen much less rough project XJRs sell for a few thousand dollars. Part out the current one and use $ towards purchase?
 
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Old Sep 25, 2025 | 01:05 AM
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Hi.
the battery is new and every fuse on the car has been checked. I'm too deep into it to walk away now, besides, I'm not a quiter, if we all scrapped them their wouldn't be any left.
 
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Old Sep 25, 2025 | 02:55 AM
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The electrical guides on JagRepair.com - Jaguar Repair Information Resource will probably help as they show all the loom routings etc.

There are some unused connectors in the boot, they only exist for use in transport when the cars where new. Plus they seem to all be wired for everything so if your car hasn't got every single toy fitted there's going to be spare connectors.
 
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Old Sep 25, 2025 | 05:57 AM
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Those codes relate to stuff that isn't plugged in. I can say if a driver door module isn't present, it wont start.
Similar thread here
https://www.jaguarforums.com/forum/x...nostic-175936/

Basic checks for non starts on R's...
Remove the battery cables....
Earth strap between body and engine, boot earth to battery, any signs these need refreshing do so. Locate the clicking relay and see what it controls, work forward/back of that to find an issue.
under the bonnet...
The big bore black power cable to the brass mount near the brake servo, needs to be a bright connection (on everything)
Other side, the fuses boxes and their link lead - tidy all connections and their earths running down to below the headlights, on a panel.

Get all the modules plugged in even if you have to remove door cards and your Canbus network completes so checks and codes can be worked on.

Which side are the black and black and grey wires in the footwell? Kickdown switch?

A couple of things to get on with.
 

Last edited by Sean B; Sep 25, 2025 at 06:17 AM.
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Old Sep 25, 2025 | 10:59 AM
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Hi Sean.
the wires are in the drivers footwear, fastened to the side body work
Ive coiled the wires up for clarity.
Ive coiled the wires up for clarity.
 
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Old Sep 25, 2025 | 11:04 AM
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I've reconnected the doors and still no crank!.
the dash errors are down to gearbox, failsafe mode and incorrect part fitted!....what ever that could be.
I've tried the other things you suggested apart from tracing back from the clicking relay, which I've pictured.
Its obviously the brown one!...lol.
Its obviously the brown one!...lol.
 
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Old Sep 25, 2025 | 01:01 PM
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Originally Posted by Howarddc
Hi Sean.
the wires are in the drivers footwear, fastened to the side body work
Ive coiled the wires up for clarity.
Ive coiled the wires up for clarity.
Those look liks pins that have been removed from a connector. I uncoil and find a connector they reach.
 

Last edited by pcolapacker; Sep 25, 2025 at 01:04 PM.
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Old Sep 25, 2025 | 01:11 PM
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Sean.....your a blooming super star!!!
to fixed it by...erm, well getting me looking in the right place!
The relay that was clicking was for the auxiliary supply, looking at the wiring diagram I noticed that the other side was the ignition relay.
so having a poke around and belling out the fuses again I disturbed a ruddy big black cable, or I should say the end of it!.
A grope and a tug and the other end appeared, both were hidden behind the loom.
he must have cut through it with the angle grinder when he chopped out that sides floor pan.....she's now showing traction and stability control fault messages but she's cranking! (Not started yet as I drained the fuel out, with this much welding I'm not taking any chances!) but I recon I've broken its back now that it crank

s 😁😁
Thanks pal👍🏻
 
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Old Sep 25, 2025 | 01:15 PM
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Originally Posted by pcolapacker
Those look liks pins that have been removed from a connector. I uncoil and find a connector they reach.
I've already mentioned that they have pins connected suggesting that they are from a block connector and that i cant find anything within its 500mm range, hence why I'm asking if anyone actually knows where they live.
 
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Old Sep 25, 2025 | 01:18 PM
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Not sure if this helps, but I was stumped when putting gas tank back in my 03 XJR because I had an extra connector. Needed to look at my 02 to figure out this connector went nowhere. There are one or two connectors by the battery that also go nowhere. I don't think the wiring is exactly the same for your '98 compared to '01 and later so double check what electrical guide your using.


 
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Old Sep 25, 2025 | 01:34 PM
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Yeah, I've noticed that there are more than I need!... very anoying when I didn't start the strip down as I tend to take pics or label stuff.
I think I'm onto of it now tho....apart from the two pesky wires in the drivers footwell!.
I'm sure their use or lack of will soon become apparent if no one actually identifies them before then.
 
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