Hi all,

I dont know if anyone has experienced the same symptoms but I am now confused.

The car (a 98 XJ8 3.2 Sport automatic) failed its MOT on rusty floor (Both sides), a suspension balljoint and a brake pipe.

I have done all the work, got the car back off the axle stands and when I reconnected the battery I now have the tell tale lamps on the dash lit up permanently along with the instrument illumination.

By permanently I mean all the time, without the key in the ignition and with the doors locked.

It is also displaying gearbox fault, incorrect part fitted and stability control fault on the screen, although this disappears when the key is turned to the ignition stage.

The odd thing is that the car is still starting and driving fine, fires up straight away, and the battery shows 12.3 volts across the terminals with the engine off.

I disconnected the battery when I was welding, and I have checked the wiring and I don't think I have cut/burnt through any.

Any thoughts?

As everything is working and I can't find a cut wire I am wondering if the welding has somehow fried a relay or the alternator?

Regards,

Alasdair.

12.3 sounds a bit low to me, and these cars DO NOT like low voltage. I would check that you are getting a good voltage across the terminals with the engine running. Also, may be an idea to do a hard reset - disconnect the negative ground terminal and hold it to the positive for around 30 seconds to discharge the capacitors in the various modules.

Thanks for the advice, I will charge the battery and try again.

I tried the hard reset last night and it made no difference.

What I find odd is the dashboard / warning lights being on all the time, but the engine starts easily. Seems to be the opposite of everyone elses experience...

Alasdair.

WAG: you have a door open (or it thinks one is . . ).

Update: I have charged the battery overnight, cleaned up the earth points and swapped each of the brown 5 pin relays in turn.

No change, the car starts and drives fine, but with the key removed the dials are illuminated and the warning lights are on.

The display screen still shows fault messages.

When the key is turned the warning lights go out and there are no messages.

I have attached a couple of photos taken with key out.

Does anyone have any other thoughts?

Thanks, Alasdair.

Dash, no key in ignition.

Make sure the little door in the key slot closes when you remove the key. It might sense that the key is still in the ignition.

Find the fusebox in the left hand (passenger side in a right hand drive car) rear seat footwell. Remove the brown relay and see if the ignition stays off now. If yes it is probably that relay that is bad. If no, the heat from welding may have damaged the wiring or circuitry in or near that fusebox.

If none of the above locates the problem, write back. The ignition switch actually switches ground signals in this car, and ground currents from electric welding might have damaged it.

Hi, thanks for the advice. I removed the relay and there was no difference.

I will need to have a look at the wiring, but there was nothing obvious.

Regards, Alasdair.

Hello again,

yesterday I went back to the car and tried the hard rest again (apparently I should turn the key in the ignition whilst the battery terminal wires are touching) - no change.

I took the wood veneer off and removed the instrument pack, unplugged it blew into the plugs and put it back - no change.

I am going to un-tape the loom through the car this week and check every wire from end to end in case I have missed one with damage from welding, but other than that what am I left with?

My thoughts are the body processor module or the light dimmer module?

I noticed that when the key is out of the ignition the gauge lights are not affected by the dimmer switch.

When I turn the key to position 2 they are dimmed by the switch, so the supply is coming from somewhere other than the dimmer module output (I think).

Does anyone know which wires should have power at the gauge pack with the key removed? I will have a go at measuring them with a multimeter when I have time this week.

Regards,

Alasdair.

With the battery disconnected unplug the gauge pack again.

Find position 2 (a white wire with a green stripe) on the LARGER of the two connectors. This is the wire that supplies ignition switched power to the instrument cluster. Using a small screwdriver gently depress the metal tab on the pin inside the window on the connector and withdraw this connector contact.

Now plug the instrument cluster back in and make sure the white/green wire is not touching anything. Reconnect the battery.

If the problem still exists, you likely have a short or other electronic failure inside the instrument cluster and you should not see any voltage on the white-green wire if you check it with a meter.

If the problem goes away now, the fault is somewhere else and you will likely see +12v on the white-green wire with the ignition off (which should not be the case).

Hello again, thanks for the suggestion. I tested the green and white wire, and it is only positive when the ignition is at stage 2.

I took the instrument cluster out and dismantled it sprayed with switch cleaner and inspected with a magnifying glass, but no visible sign of damage.

I have remove fuse 18 from the left hand fusebox which kills the battery positive feed to the instruments, and that has turned off the lights.

As the lights and gauges all operate correctly with the ignition at stage 2, and the cluster remembers the mileage I think I am going to take this as fixed for now. I will look for a secondhand cluster at some point.

Again, many thanks for the fault finding tips.

Regards,

Alasdair.

I have the same problem but removing fuse 18 did not do anything. I replaced the ignition switch no help. I disconnected the ignition switch--nom help.

check for loos ignition wire I just had the same thing yesterday when I got mine back and that’s what they said

My sun roof on my 98 die super charger needs new track can anyone direct me where to find one

[QUOTE=n8thegr8;2405575]My sun roof on my 98 xjr super charger needs new track can anyone direct me where to find one.

Reactivating a 6 year old dead thread, with your multiple posts is unlikely to attract help.

Suggest you follow the advice to post an intro in the NEW MEMBER section, where you will find great advice on how to use the Forums. This will include when and how you should start a new thread.

Best wishes,