Ran yesterday after jump. Now only response to key turn is loud "click". Battery charged good connections, won't jump again either - only "CLICK".

 

Hi TCSchmoe,

Welcome to the Jaguar Forums! It's great to have you with us.

I have moved your post from the forum for the X350 to the forum for the X308, which is the Jaguar factory project code for your 1998 XJ8.

Are we to assume that the reason you had to jump the car is that it has been sitting for awhile without running and the battery had gone flat? If you had to jump it for some other reason please give us the details.

Assuming the battery had simply been depleted due to the car sitting unused, the first thing I would suggest is that you measure the battery voltage across the battery terminals while you are attempting to crank the engine. Jaguars require very healthy batteries and it's possible that even though your battery appears to have charged well it cannot provide the necessary current to power the starter.

If the voltage at the battery doesn't sag below 11V while cranking, you can then check the voltage in the engine bay to see if you have a large voltage drop between the battery and starter/alternator.

Probably 8 or 9 times out of 10 the kinds of problem you report are due to a battery that has been so badly depleted that even though it appears to retain a charge it can no longer supply the necessary current to run the starter. You might try jumping the car again, but before you try to start it, allow the battery to charge for 10 or 15 minutes from the running jump vehicle. That has usually worked for me when the battery was the problem.

There are plenty of other possibilities, including the ignition switch, but my next suspect might be a relay such as the Starter Relay, Ignition Positive Relay, or Engine Management System (EMS) Control Relay. You can find the locations of these relays on the diagram on pdf page 30 of the 1998 XJ Electrical Guide, which you can download free at the link below courtesy of our forum member Gus:

http://www.jagrepair.com/images/Auto.../jagxj1998.pdf

Hopefully others will respond with additional suggestions.

In the meantime, please visit the https://www.jaguarforums.com/forum/n...-intro-must-5/ and post an introduction so we can learn something about you and your Jag and give you a proper welcome.

Cheers,

Don

 

+1 to Don B and to add to that, check your positive terminal for corrosion. If there is any corrosion on it, I'll pretty much guarantee you its down in the lead and you'll never get it out and absolutely should be replaced. It can and will prevent full voltage from reaching its needed point.
Get the battery tested, if you've not done this before, they will put a boost charge on it and read the charge rate and drain rate to check the cells. This can be done at any Autozone, O'Reilly's, Sears or your favorite parts place.
As for jumping your vehicle (or any vehicle for that fact), I do not like the old jumper cable procedure. It can do harm in a number of ways (more to the jump vehicle), so I recommend the newer way and that is use a antigravity microbattery power source. They have safety features built in to prevent wrong connections and over running of the starter and burning it out. Power is immediate and there's no waiting, like a new battery. You can literally remove your terminals and attempt to start your car with this device . There is a difference between cheap ones of these and a pricier ones, so be sure to look for those safety features. The one I have is the XP-10, one of the more expensive ones, but it has worked flawlessly for me. They have many versions now (since I bought mine) and they do more than just jump a vehicle. They can charge your laptop, phone etc.... Yes, there's cheaper, but do your research.
Also, if the vehicle sits for over a week at any given time, get a Battery Tender. It will chase away many electrical ghosts by providing a constant full charge and monitor of your battery until you pull your girl out again.
To add to this, do what Don B said and download your electrical diagram. Check your grounding points and clean as necessary to assure a good contact.
Jags really like fresh batteries, so keep yours up to par and you'll see minimal to no issues electrically....like mine...

 

Attached is a great troubleshooting guide one of the forum members put together some time back. I have had success in the past following the examples illustrated for No Start conditions.

 

 

Fuel is irrelevant if it won't crank.

 

Hi Fugicakes,

Welcome to the Jaguar Forums. It's great to have you with us.

I note from your new member introduction that your Jaguar is a 1998 XJ8. I can't think of any reason that your VIN would make the troubleshooting guide from Rob any less valid for your car. Vern posted the link to Rob's troubleshooting guide in post #4 of this thread. In order to diagnose your no-crank issue you will need some basic tools, including a voltmeter-ohmmeter or digital multimeter. A serviceable one can be purchased for less than $20 from most auto parts stores, as well as Harbor Freight Tools, Northern Tools, pawn shops, etc.

Please keep us informed.

Cheers,

Don

 

 

How have you actually tested the battery? Jaguars are very sensitive to battery voltage and cranking amperage. If the voltage falls much below 11 volts while cranking, the Engine Control Module (ECM) will not trigger the ignition to fire. Recently I have tested batteries in client vehicles with static voltages over 12.5 volts, which would generally be considered acceptable, but my Midtronics EXP-800 analyzer found that the batteries were only capable of delivering less than 50 Cold Cranking Amps, even though they were both rated to deliver more than 650 CCA. Have you made any progress following the diagnostic steps in Rob's troubleshooting guide?

Cheers,

Don

 

Hey!

I had this problem the other day, would not start or crank, just a loud click, battery was fine. In the end it turned out to be the Immobilizer! After unlocking my car the Immobilizer had not came off. As my key-less fob does not work I had to get round this by disconnecting and reconnecting the battery, but make sure you know the code for your stereo if you do this!

 

Hey Louis, have you tried this for your fob?.. ... https://www.jaguarforums.com/forum/xj-xj8-xjr-x308-27/fob-batteries-battery-upgrade-210090/ or if you need another... https://www.jaguarforums.com/forum/x...t-fobs-209575/