Exciter ring?
 

Morning, all.

My 99 XJ8 has an intermittent problem. When I turn my ignition key to the start position, the lights come on, the steering wheel and seat move into place, but the starter does not crank. Typically, I turn the key to the off position, turn it back to the start position and the starter and engine fire.

The problem seems to be getting worse.

I did a search and found a few comments about the exciter ring around the ignition cylinder, but few details. Is this an item that can be purchased separately? Or is it an assembly with the ignition switch? Or is this indicative of a battery that needs replacing?

Thanks in advance.

Pull the cowl around the column. The exciter ring is the black plastic ring around the ign switch with 2 wires. Unplug and the ohms should be 33.4. Anything else and replace it. Yes theyre avail seperatly

Earsti and Brutal, when the exciter ring is the problem, would the starter solenoid still click? I ask because a few days ago our VDP wouldn't turn over, but I heard what I assume was everything energizing including a click that I believe was the starter solenoid. Although all the warning lights lit up, I decided to try to jump it and hooked up my Powerstroke pickup to jump it. Still did not turn over.

Then when I closed the hood and dropped down on the ground to see if I could reach the starter with a hammer, my wife tried it again and it turned over and immediately started. Other than the overheating/thermostat issue this week, it has ran/started good...until tonight. Same thing, nothing but what I believe is a single click at the starter...then a second click (more of a release) when I let off the key.

So, what do you think...exciter ring...or starter?

In my case, when I turn my key, there is nothing. Not a sound. It's as if the battery is completely dead. No clicks.

I turn the key back, as if to remove it, and turn the key forward and it starts. This happens not quite once a week. If this were more of a daily thing, i'd go ahead and take care of it, but for now it's way down on the list, (unlike mys rear suspension).

Back to your question. It sounds like the starter. If you had an overheating problem, I'd bet a few dollars the armature in the starter has started to swell. The armature is what spins inside the case when the starter is engaged. If it has swollen, then it binds up as it trys to spin. Make sense?

Have seen this on several cars (not a Jag, yet). Heat can kill a starter.

Good luck.

Thanx for the thoughts Earsti. Fortunately, it was just the power lug connection under the cover on the passenger side. Funny thing is, while I was working on the failing thermostat problem this week, I actually looked at the discolortoin of the boot a couple of times and wiped it down. I never bothered looking under the boot at the actual connections until after reading another post about starting problems that eventually led to the discovery of a loose and overheated/melted connection at the lug. Sure 'nough...ditto. Loose connection on the engine side of the false firewall and a melted insulator that coated the lug and the washers...resulting in a very poor connection. Most likely is also the reason the battery was low on the charge a few days ago.

We still have the intermittent courtesy light issue where the lights come on occasionally while driving and where the memory adjustments and tilt controls don't work...but I've tracked all those issues down to being associated with the ignition switch and have found that if I turn the key back just a tad after starting, all is okay and everything works well.

One thing...then another. :icon_doh:

Hi all, I'm new here and I'm experiencing a similar situation with my 1999 XJR. Ever since I bought the car back in 2004 I've occasionally had issues starting it. I'd get in, turn the key, and nothing, no noises, no lights, nothing. Normally I could turn it to the off position, then try starting it again and it would start as normal, sometimes taking a few attempts. At the end of last year a whole new situation began. I went out to start it one day and when I did, I just heard a click, which I assumed was the starter solenoid, then the windshield wiper would cycle once and stop. At first I figured the battery was probably shot even though the voltage checked fine. I tried jump starting it but that didn't do it. Just to be safe, and since the battery was the original one, I replaced it, still nothing. I went through checking all 144 fuses, they all checked good. Reading elsewhere on the web that the main key might have possibly lost it's coding, I tried my green valet one, I only have the two, still nothing. Aggravated and since this isn't a necessary vehicle I let it sit. A month went by, two months went by, I'd occasionally try to start it but nothing. Finally, I had to move it since it was tying up the back of my driveway so I hoped in to give it another try and bam, it fired right up. As risky as it was, since I still had no idea what had caused the problem, I drove the car and it did great. It started fine with no problem for the better part of two months. Unfortunately last week, after it was starting and running great, I hoped in it to go for a spin and the same damn thing happened. I turned the key, heard the click, the windshield wiper cycled once and then nothing. Luckily both times this has happened I've been at home. Since then I've checked the main power cable connection at the passenger side firewall, under the plastic cover, and it was okay, nice and tight. I dropped the bottom cover of the steering column and see the exciter ring but can't get to where it's plugged in. How do you drop the column on a Jaguar XJR? On most cars it's simply a matter of loosening two nuts that are easily accessible, I don't see anything of that nature on this car. What exactly is the exciter ring? Is it part of the security system? Is it a pickup that reads the code from the key? I love the car but considering all the issues I've had with it I clearly must be a glutton for punishment. Any help or suggestions would be greatly appreciated.

The exciter rings is a transponder that reads the key. If the signal rec'd is correct, then the starter will engage when you turn the key.

As I understand it, when the exciter ring is replaced, the keys needs to be synced with the ring.

I have not taken the time to replace it, as it has been such a minor irritation I am just ignoring it for the time being. I am chasing a clunking sound in the rear that is more bothersome.

I have not had any other issues as you have described them. Sorry I can't be more help.

The exciter ring is really just an antenna basically. Replacing it does not require any programming or re-syncing. Your description is a classic for the failure of the ring.
Part number is LJA2668AB, parts catalog calls it a key transponder coil. It's only about $30-$35. How's that for an inexpensive Jaguar part??

Cheers,

I had a lot of these issues, and it turned out to be the ground strap under the car. NOT the ground strap for the battery (but it looks just like it). Get the car up and look for the ground strap about a foot inside of and behind the front passenger tire. If it's loose, corroded, or worn, replace it. It's held on by two bolts. Quick, easy, and it did the job for me.

All props go to Brutal, who gave me advice on this forum where to look. Thanks again!

Good luck!

Your initial post on this matter alone has been a major help, until seeing it I had never heard of an exciter ring, let alone knew for sure what it does. I was figuring that due to all of the various control modules throughout the car one of them must be the culprit. One that would probably cost about $2k and be impossible to find. So, many thanks, for the possible lead.

Not having to program or synchronize it is great to hear, as well as hearing this sounds like it could be the probable cause. It doesn't get any better than being given the part number, catalog description, and price of the part, unless you would care to install it for me, LOL. If this solves the problem it's sure going to cost less to fix than I expected, that's the kind of Jaguar part I can deal with. Now I just have to figure how to get to the plug. Thanks

Oh man, that would be too good to be true if that's all it is. I'll have to check that out this evening. Thanks, I'll let everyone know how it goes.

Well, unfortunately it's not looking like either of those suggestions are the answer to my problem.

Last night I checked out the ground strap and other than it being a little dirty it looked fine. Just to be safe, I removed it and cleaned up its contact points, and the bolts and their threads, with a wire wheel in my battery drill, to ensure it had a good solid ground. When I went to start it, the same thing, click, windshield wiper cycled once, then nothing.

This morning I finally got the steering column tore apart and removed the exciter ring. What a PITA, had to remove the steering wheel and turn signal cluster just to get at the exciter plug. Actually, now, after figuring out how to do it, it wasn't really all that bad. When I checked it's resistance I got 33 ohms, according to Brutal's post above it should be 33.4 ohms. I'm inclined to think the four tens of an ohm difference could be due to the testing meter itself. If it's essentially a coil, like I'm assuming, there's really only two things that can be bad, a break, or open circuit, which would give no ohm reading at all, or a short, and what would the possibility be that due to a short it was only showing a difference of four tens of an ohm? None the less, just to be safe, and since I have it tore apart, I ordered a new exciter ring. Hopefully it'll be here by Wednesday of next week. I'm still hoping it might do the trick but I'm inclined to think it's not the problem.

With the column opened up I see a little metal rectangular box labeled "Key Transponder Module" to the right. Does anyone know if there's a way it can be checked?

I certainly appreciate these two suggestions, and maybe replacing the exciter ring will fix it, but I'm open to other possibilities if anyone has any.

Sorry to hear it wasn't an easy fix (yet). Since you've already checked the bulkhead fitting and the ground strap, I would take a look at one more place before full-on troubleshooting.

In the trunk, behind the spare tire, is a black plastic box. Remove the lid and inspect the condition of the box and contents. Sometimes this box is cracked due to the tire being chucked in there carelessly. This can cause arcing and malfunctioning. If it's cracked and damaged, replace the box and contents. If not, move on to troubleshooting with a good digital multimeter.

I'll link to a post dealing with an issue I had. Even though my cure ended up being simple, I chased the rabbit pretty far down the hole anyway. Before doing anything, make sure the battery is good. I know it's new, but I'd slow charge if necessary and load test it anyway. Then I'd test the alternator (you don't have to remove it to test it). If those two things are good and out of the equation, it's all about electrical diagnostics from there on out.

Hope this helps.

https://www.jaguarforums.com/forum/j...rt-argh-56557/

I'm standing pat on the transponder coil. I've many times proven a BAD coil with resistance, but I've never proven a coil GOOD with resistance tests. So I'll hang my hat on the replacement coil as the final fix.

I've been wrong before................

@Ricop.

Let us know what happens after your swap of the exciter ring.

Good luck!

Hey everyone, no exciter ring yet. I ordered it on Saturday and received an email yesterday saying my order was being processed. I thought for sure I was going to get another email yesterday saying it had shipped, but that didn't happen. Nothing today either, so no telling how long it's going to take them to process the order. Maybe they'll surprise me and I'll find it sitting at the front door tomorrow.

No problem though, just as typical, I was doing a little maintenance on my main use vehicle, a Jeep Grand Cherokee, when I noticed I had a bad tie rod end and one of the CV joint axles boots was shot. So I've been farting around with that lately.

Whenever the ring comes I'll let you all know what happens. I'm still hoping it does the trick, that would definitely be an easy fix. With all the various control modules, such as the one mentioned above, that I probably won't have a way of checking, I dread the thought of having to go too deep into troubleshooting.

A brief follow up, the exciter ring did make it to me on Friday. I tested the resistance of it and it was only a few tenths of an ohm different than the one removed. Even so, I had my fingers crossed and was hoping for a miracle, unfortunately my miracle didn't happen. Once I got everything plugged back together and in place, I turned the key, and......CLICK, the wiper cycled once and that was it, no start.

When I get back to working on it I'm going to start double checking grounds and feed cables and their terminations. For now though I have other priorities I have to take care of. Yeah, I'm pretty frustrated but I appreciate the suggestions they were definitely worth a try.

that wiper inssue is very indictive of poor battery voltage. you need to do a voltage drop test when trying to crank. there should never be more that .2volts drop between the battery terminals and the terminal on the starter or alternator. same with the grounds. check em because youre issue to me sounds like youre loosing power when you go to start and check the battery under load when trying to start. there are many times a battery checks good on voltage untik you ask it to work and then...........
you issue with the wipers I see alot when i go to start cars in the parking lot with weak batteries or power transfere issues like cables.