Have you tried disconnecting the cars battery (only do this if you have the radio code..) wait a moment then reconnect the battery and the alarm should chirp. press the keyfob after each chirp, it should respond, until it has chirped 5 times.
if the system doesn't respond then maybe the fob battery needs replacing. Does the fob lock/unlock the doors ?
Did you download the above files ?? The first show how to use the alarm, the other show where and how the alarm is fitted.

 

Some of he files listed don't pertain to my problem. My valet switch already exists on my steering column. I have disconnected the battery and tried with no luck. I have turned the ignition switch on, valet switch off, ignition off valet on. 5 to 12 rocks of the valet switch, nothing. When I purchased the xjs, it came with a mangled remote. in pieces, but still worked . It wasn't until I tried to program a new remote that the system quit working. I have since bought yet another remote. When I tried it, I got some kind of warbling sound out of the car but when I pressed the remotes, no horn beeps and no door locks. I'm thinking maybe after I do the on off stuff I will try and remove the key from the ignition as described in the '94-96 instructions. I'll try that today, along with the battery disconnect and programming functions.The latest remote has matching FCC numbers to the original. Working on this now for 6+ years on and off.

 

The files listed don't pertain to my problem. My valet switch already exists on my steering column. I have disconnected the battery and tried with no luck. I have turned the ignition switch on, valet switch off, ignition off valet on. 5 to 12 rocks of the valet switch, nothing. When I purchased the xjs, it came with a mangled remote. in pieces, but still worked . It wasn't until I tried to program a new remote that the system quit working. I have since bought yet another remote. When I tried it, I got some kind of warbling sound out of the car but when I pressed the remotes, no horn beeps and no door locks. I'm thinking maybe after I do the on off stuff I will try and remove the key from the ignition as described in the '94-96 instructions. I'll try that today, along with the battery disconnect and programming functions.The latest remote has matching FCC numbers to the original. Working on this now for 6+ years on and off.

Okay....tried the additional steps and nothing. Therefore I am now done with it. Thanks for the attempts by everyone to help me fix the problem.

 

Hi Again malc4d, first I want to thank you for all the help you provided to me today. It was above and beyond and very much appreciated. I can't thank you enough. I replaced the burned out fuse and the car immediately began intermittent beeps not horn). The sounds continued until I removed the fuse. The security battery was DOA. It even had the date of manufacture as August 1992. I have ordered a new one from Batteries plus. Thank you for that info. Was the system beeping because it could not find the security battery?

 

Glad that l could help you. Remember me saying that you will have to program the fob(s) to the alarm. After each of those beeps you must press the key fob, this will be acknowledged with a longer beep by the alarm . You MUST press the fob after the beep. If you have more than 1 fob that must be pressed on the second beep and so on until you have received 5 reply beeps. It will continue beeping until you do that.

 

I remembered but the system just keep chirping along. That is why I asked if it's because the old dead security battery needs to be reconnected temporarily to complete a circuit..

 

No, the backup battery isn't the problem. I suspect either the fob battery is weak or the fob isn't working...….should be 318 MHz part # dbc 100842 It also will only work just a couple of feet from the alarm. Really close lol

 

okay. I was able to get the mangled fob to come to life. Made my day. Tried the new one, still nothing. However, I remember you telling me to disconnect the vehicle battery and reconnect and try that so that will be my next step. The original remote came back to life as soon as I put the new fuse in. It programmed and I went thru the 5 beeps.
(what a long strange trip it's been)

 

As mine is 418 MHz and all the ones l see on flebay are 433 MHz, I bought a new fob and just replaces the internals with my 418 internals. simples.... Sometimes just a new case comes up.

 

Well, I'm very happy to have my old mangled fob working. I did try and unplug the negative on my car battery but the new 318mhz fob still won't program, even with a replacement new battery. However, now that the old fob works I'm just going to sit in my garage and play with the fob for awhile. I'm happily beeping along.
Thanks again Malc.

 

Greetings; So happy to have found this! Have a '93 XJS V12 (VIN180302); 65K miles. Was perfect. Parked; went out the next day... Lights come on; buzzer sounds; turn key... nothing; not even a click. Have read the entire thread. Have had security system issues with the other Jag (XJ6), but knew how to reset it. First issue now is that I do not have a fob (never have), but never worried about it. Hoping that his issue is something this simple and not a greater probleme (electrical, starter, etc). Suggestions, otherwise? Thanks in avance.

 

Try unplugging the big white connector in the trunk. But l recommend getting a keyfob ..

 

Merci, thanks for the help. Still down. Guess it's to the shop in the a.m. Ugh. And, will try to find a fob. Will either work or must I get one from Jaguar? Thanks, en avance, again.

 

It depends on when your car was built. My '93 was built in September of 92 and so uses the 92 alarm system. Later year models used the newer system. I know this as Malc4d helped me find this out after 6 years of frustration.

 

Seach ebay
https://www.ebay.com/itm/1993-96-JAG...wAAOSwgope-PHA

 

This a great and very helpful thread. I am the proud new owner of a beautiful 1993 XJS coupe. Inboard brakes. It came with two fobs that don't work. I have an on/off switch on the steering column.

I read this entire thread. I would really like to remote lock and unlock.

What I've tried:
1) Disconnecting the battery. Trip computer clock resets, but I hear no chirping.
2) Following instructions for toggling valet switch. No chirping.

I noticed an unplugged connecter in the alarm panel. I've attached some pics.

Thanks in advance!

Connector

 

After going thru what your going thru now, malcd told me there is a fuse on the wiring harness you show in your picture. It is a black fuse holder that is taped to the black wire harness and hard to see. It contains an alarm fuse. On my '93, that is what stymied me for 6 years. It's really hard to see, but it is what kept my system from working. If it is bad, replace it and then try disconnecting the battery again. If your vehicle was made before 1993 (a 1993 made in 1992) that is what will work for you.
If your vehicle was made later in 1993, the valet switch and ignition key process is what you should try. Don't forget either way to hit the buttons on the fob 5 times total for all.

 

Put new batteries into the fobsfeinsta.

Please go to post #32 and #45 and download the alarm fixing and instruction file l posted. These will help you sort out the alarm.


The plug you show fits into this "nudge or bump " module. Which seems to be missing in you picture.

You have the backup battery module which has the black and red wires but the battery will be deader than a dodo. I got a similar battery from batteries + that fits (Just)
Also you will see the 2 plugged yellow wires, plugged together as yours are will set up a "passive" alarm mode. This will set the door alarms but not lock them when you leave the car. Unplugged the alarm and locks only work with the fob.
Also as nothing seems to work as Rick said above. Check the inline fuse hidden in those cables.

The on/off switch is a so called valet switch which you will never use. Leave it in the off position.

Put new batteries into the fobs. Remember that these have a very short range, you must be nearly touching the car. OR you can hold them to your head, this WILL REALLY extend the range a bit....odd but true.

 

Fobs have new batteries. So if I want the door locks to work (kind of the whole point for me), do I need to do something with the yellow wires? Also- does the backup battery need replacing to get the system working? Seems to be mixed answers on that.

 

1) No, the yellow wires do NOT lock the doors, they just arm the alarm.. if you opened the doors after leaving the car the alarm will sound. Default is unplugged but up to you on that one. As nothing is working check the fuse...

2) No, the battery back only keeps the system live for a short time. Like disconnecting the battery for a few minuets ..

Download my files as above. They will answer many of your questions.... Check that fuse.
As you don't have the nudge box l would assume that might have caused a problem at sometime.

One you have replaced that fuse and you have the radio code to hand, disconnect the battery and wait a few minuets the reconnect it. If all is well the alarm will chirp, after each chirp press a fob and the alarm will answer. You must do this 5 times, if 2 fobs the must both be pressed then 1 3more times after that.