Red,

Look at this diagram in the link below, Item 14

Relays and Control Units - Parts For XJ6 (2.9, 3.2, 3.6, 4.0) from (V)500001 to (V)667828 | Jaguar Classic Parts UK

Bookmark the above website for future reference of locations and proper OEM part numbers.

 

Thanks again Rob,
I feel I am monopolizing your time here my friend...... I do apologize.

Ok I have bookmarked the page and yes I see item 14.....
actually I had my suspicions that may have been it.... but I convinced myself that was the wiper module.

I will have to try and see if that is working correctly....
Would you happen to know if/how the wiring/module can be bridged to force the speaker to sound? Just to test the system.

 

It appears there is one connector to the warning module - LB58

warning module

outputs- Active - Inactive
LB58-5 voltage to speaker - signal - voltage 0v
LB58-6 ground - ground - ground

inputs; - Active - Inactive
LB58-1 turn signal - staggered pulse to ground 0v - 5v
LB58-2 seat belt/linear switch - timed pulse to ground 0v - 5v
LB58-3 key insert - ground 0v - 5v
LB58-4 power ground - ground - ground
LB58-7 battery power - 12v - 12v
LB58-15 logic ground - ground - ground

Central processor

outputs; - Active - Inactive
LB14-14 turn signal - staggered pulse to ground - 5v
LB14-15 seat belt, gear position audible - timed staggered pulse to ground - 5v
LB14-16 key insert - ground 0v - 5v

inputs; - Active - Inactive
LB12-2 battery power - 12v - 12v
LB13-1 ignition power - 12v - 0v
LB13-19 ignition key - key in: ground - key out 1v
LB13-22 seat belt - fail: ground - pass: open circuit
LB13-23 seat belt - fail: ground - pass: open circuit
LB13-29 not in park (linear switch) - fail: open circuit - pass ground
LB13-36 logic ground - ground - ground
LB90 logic ground - ground - ground

column switch (key)

output; - Active - Inactive
LB55-19 key insert - key in: ground - key out: 1v

input
LB55-22 speaker audible - ground - ground

grounds;

LBG75 - bulkhead behind blower
LBG88 - passenger footwell, right A post

keep in mind,this is of the schematics for LHD, but I would think it would be close

 

I should imagine it would be the same.... except possibly LBG88 passenger footwell, right A post will probably be left A post lol

So any idea what I would need to cross or bridge just to get it to react and send a signal to the speaker?

 

I think it may be better to read the voltage output from LB58-5 (voltage to speaker), instead of risking a unintended short elsewhere. Simply having key in with door open should cause voltage output to the speaker.

No output, then you'll need to see if there is voltage signal coming into the module from LB58-3 (key insert), or you could check that first. If there is voltage in, then the module is suspect.

You might just consider removing the module, opening, and examining for the infamous cold solder joints, which are so famous in these cars.

 

Thanks again Rob...
I will do that tomorrow....
I agree.... better to test the voltage outputs rather than shorting something else.
I can see I am going to have to invest in a big magnifying glass with this car..... specifically for looking for cold solders.

I was just looking through a PDF i have (88 Sedan Intro.pdf).... it shows the workings of the Central microprocessor.... including the position of the audible warning output and the input for the audible warning logic unit.

Doesn't go into any great detail how to test them..... but shows how they work together lol

 

ok buddy...... it is now 1:30 in the am...... time for me to hit the sack

Goodnight..... morning for you lol

 

update:
Got under the passenger side dash and pulled the wiper/warning module to check it out..... everything looks ok there, not that I really know what I am looking for.

However whilst under there I started finding wires that did not look like they belonged....
I traced them through and found they had been added...

first wire I noticed was to the ignition relay (main white wire) it had been cut and then two long green wires added, going behind the console and across to the driver side.

At the end the two wires were not connected to anything and had just been twitched together.

The next splice I saw was to the central locking module..... again traced it to nowhere.

Then yet another wire (black) that I traced from ground also leading nowhere.

The next wire came from the (I think) ECU or possibly cruise control module (big silver box)

My conclusion is that at some time there was an immobilizer and car alarm fitted that had since been removed leaving the wires behind.

I have now removed all those wires and rejoined the thick white wire from the ignition relay....... looks a whole lot neater now.

This however still does not solve the existing problem of the audible warning device.

I guess next step will be to check the central processor unit connections and solders.

Will keep you all informed of any developments

 

decided to play it safe, today I went out to the car and removed and replaced the column speaker....
I have had a success of some description....
I now have audible clicking when I engage the turn signals..... previously there was no indicator sound at all.

I am not sure what the sound is supposed to sound like.... but what I am getting is a low'ish clicking sound.... almost like a dial tone on a phone or the sound of an old pendulum clock ticking. Could also describe it as the sound of touching two wires together... kind of grating not really a tone as such. (it is not easy to explain a sound)

however still not getting any other audibles at all, not key in, seat belts, linear switch or anything else.... only turn signal.

Does this shed any light on where I should check next?

 

Red,

I added some additional information to the post from yesterday where i listed all of the output/input connections. I added "active - inactive" states for each connection for you to meter at the pins.

Based on the information you discovered, I'm wondering if the PO fried something, only way to tell is to meter the pins for appropriate output/input readings.

I still think you should open the warning module and look for bad solder points. The module isn't widely known to be affected by poor solder points, but based on the undocumented wiring found, may be worth a look.

 

Thanks Rob.. I will pull the warning module again, I did remove it and take it out of its case the other day just to look at the internals and see if there were any obvious faults.
There was nothing obvious at all, but that doesn't mean there is no dry or cold solders.
My eyesight is not as good as it used to be and I need to invest in a large magnification glass to actually see those kinds of details.

I will keep plodding along and will eventually figure it all out..... and keep you all updated on my progress (or regress) lol