So about a month ago, the Cat started to get the fuel gauge issue which showed inaccurate levels. Then I began to get the airbag warning light coming on every once in a while. Then on my 200 mile journey, the traction control light would come on and turn off and then randomly come on again. Today I noticed my backup lights do not come on.I hope my Cat is not telling me something like the end is getting near. Could all of these be related?

 

could maybe be a corroded ground wire somewhere? those usually leads to all kinds of mysterious faults.

 

Coming back around to the ignition switch you might obtain one from a salvage yard as the X308 and X100 ( 2 door sport coupe ) use the same part #

It wouldn't hurt to have a spare , no new key needed

It is the ignition switch that controls electrical distribution on the car at the fuse boxes

Were you able to see if the # 5 pin of the ignition switch connector has a good car frame ground ?

After the king relays we will look at the battery cable connections

Do not over tighten the battery positive post as the special shape nut underneath there will split in 2 , ask me how I know

 

My bad I did not look at it when I have the steering wheel off. I will do that. But why would you not need another key?

 

The key barrel and the switch are separate joined on the back of the barrel

No need to remove but if you do there are 2 small set screws that is a slotted cut but is a thick dimention cut so it can fool you and with a not so wide dimension slotted screw driver

It would click around in there as you spin it out

You may have damaged the ground stud terminal on the # 5 wire , I have never seen the ground stud or the location

The ignition switch provides a ground path command to close the king relays

 

Check the voltage across the battery terminals with a voltmeter. What is the voltage reading with the ignition in the OFF position?

A failing or weak battery can cause some of the electrical 'gremlins' you're describing.

 

You would have to remove a leg from the battery for a valid test least a sneak circuit though the rest of the car like the hot at all times SLCM

When looking at the voltages around the car with the starter at rest and not at rest you are looking at a dynamic reading situation where a loose battery cable run through the car plays into effect of lower voltage reading at the fuse boxes vs , at a isolated battery , your alternator voltage generation comes into play after engine start

 

It is a pretty new battery so I am thinking it is the switch because things seem to disappear if I stop turn off the key for seems to be 15 minutes or so and start back up. I looked at removing the barrel and can't figure out how to remove it. Any suggestions. Also would the reverse light also be out because of this? I checked all the fuses and they are all good. I read on another post that it could be the rotary switch. Not sure what that is.

 

There is a Youtube video on the barrel removal and if I remember the barrel has a hole in the bottom you insert a pin to unlatch it

The rotary switch is attached to the transmission body on the left side

The rotary switch can be removed and cleaned , it has delicate fingers in it like contact brushes and the hard part is the O - ring seal around it expanding and not able to stuff it back in place

The rotary switch connector is on the top side of the car floor pan by the shift post and you can test it from there

 

Yea I figured how to pull the lock out but spent about an hour trying to find out how to pull the cylinder out and could not find anything. I know how to do it on a Saturn but not a jag. I was hoping to go to you pull it tomorrow to take one off a 1996 if I can figure it out

 

 

When removing the ignition switch do not lose the small set screws as they fall out

Take plenty of small slotted screw drivers like in a kit you probably have in your profession

On re instalation have the wings or ears marked somehow as they can be put back in 180 degrees out

Back on your # 5 wire car frame ground inspect it for a single wire strand terminal connection , this would be a cat whisker situation on a meter reading

You can read a good connection with a meter but the single wire strand can not allow enough current flow to pull the relay control half and maybe just on the edge

 

It appears that there are about three screws to take out? Hope to get out there tomorrow to pull the one off the other car. As always I appreciate your help. Should I lube it up pretty good before I swap it out?

 

I wouldn't plan on getting the rotary switch out as the connector will not fit through the hole in the floor pan

I ended up cutting the wires and mailing the part off to someone in Australia for he needed one

So on car cleaning of your original part may be a easier option

The O - ring if it has fallen out of place can be cut to remove some material to be better able to refit into place

Heavy vasoline can help hold the O - ring in place

put the gap in the cut O - ring on the bottem

 

OK change out the switch and before I put everything back together the ground that you were speaking of is underneath the console? Based on what it was saying it is attached to the LH console ground stud. It is either that or the pillar ground. I guess I will check both.

I looked further into my reverse light issue and it seems that my brake lights are also not working except for the one in the back window. Once I get the switch in I will check again unless I am missing something. I checked all the fuses and they all seem to be OK. Another grounding issue?

Update: replaced the switch still have the gas gauge going to ) every once in a while. The other issues, airbag and traction control, going to have to wait till I drive it to see if they appear again. The brake light and reverse lights still don't work. I have checked every fuse. I replaced the relays and all I get is the brake light in the window.

Update 2: Could this be the SLCM. https://www.jaguarforums.com/forum/x...orking-170295/


There has got to be something I did or changed or messed with that has screwed all these up but I just cant think of anything,

 

You can make a ground or use another one if not able to find the specific one

Wire color for # 5 pin .....

Don't forget the ears on the witch and how it relates to the 180 degrees out installation

Editing

First priority is to get your brake lights legal

Off the top of my head the brake lights use a ground path through the ignition switch beside the obvius brake switch ( the brake switch is actualy 2 switches and the ABS modual uses one of the brake switches

Your 3rd brake light is a add on design that may be independent somehow from the traditional 2

You can discern the brake switch ( s ) use in the different systems in the brake switch pin #s used like 1 . 2 , 3 , 4

Another thing that uses the brake switch is the cruise control

Someone a couple of months ago had some good pics of the brake switch ( s )

I think the switch part # was upgraded to the X308 by a TSB

This is a post of someone with a X308 going through replacement

Brake Light Switch - Jaguar Forums - Jaguar Enthusiasts Forum

This is the one I was looking for on the X300 brake switcch

Brake switch replacement repair - Jaguar Forums - Jaguar Enthusiasts Forum

Brake switch TSB

12-10 Amended (jagrepair.com)

 

Not saying you have a bad brake switch or a bad ignition switch circuit but some information on the ignition switch circuit

You may see a good meter reading on the black colored ground wire # 5

But you may be reading through a cat whisker or single wire strand or bad ground stud connection

This limiting of the current flow may cause the necessary current to keep a king relay closed being on the edge of badness

The term king relay is the relays on the fuse boxes like the ignition positive relay for the right engine bay fuse box

the pic is of the switch side half of the connector

 

The 3rd brake light which works uses pin 1 and 4 of the brake switch and does not use a ground path through the ignition switch

the normal brake lights ...........

Has the Body Prosessor module uses a ground path through the crash switch and then through the ignition switch at pin 3 to pin 5 the car frame ground on page 39

this is page 87 of the 1996 wiring guide point 8 double hash stop sign

 

After I wrote that I took off to You-Pull-It and got a Light Control Module, after reading a few posts, and replaced it and all the lights are working again. The give away was the third brake light. On a 97 R the control module I guess is built into the security module. In the XJ6 it is a separate module in the fuse box. Is the ground the console ground underneath the ski slope? Are you are saying maybe cut the ground and take it to another ground?

 

The brake lights do not use the exterior lamp control module but the BPM , odd

Still editing above post