I'm having occasional problems with my 1999 XJ8 where there is no electrical power. When trying to start the car after it has been stopped for a short time there seems to be no electrical power, i.e. no dash lights, door and trunk locks don't work, no lights, won't start. The only thing that continues to work is the clock. It never loses time. Battery is less than a year old and voltage checked on the cables is good. Then, for no obvious reason, everything works again. This problem has not occurred while it is running.


Jaguar dealer has offered no help except to diagnose the car for a few hours but no clue as to where to look.


Has anyone experienced anything like this or can give me any ideas where to look?

 

Yes I have. Your problem is not unique to Jaguar. $10 says it's either the primary ground point or positive lead to distribution block. Voltage att he battery is not relevant. Use an Ohmeter next time it happens (yes bring one with you.) Next time is happens, keep everything connected as is. Test the Negative POST (not the cable) on one end and the bolt that bolts the other end of the negative cable. DO NOT TEST or TOUCH the ohmeter to the CABLE at this point. If the cable is fine, your ohmmeter will read 0. Do the same with the positive POST on the battery and the bolt that the positive cable is connected to (aka distribution block), probably on the firewall (not the starter). You are assuming the cables are good. I'm betting you have a weak connection on one of those four points. That's where I would start.

I hope this helps

 

BTW you are also in the wrong forum for your car, and might get a better response in the X308 forum, the one for your car.

 

flynkites,

Welcome to the Jaguar Forums!

I have moved your thread from the X350 forum to the forum for the X308, which is the Jaguar factory code for your 1999 XJ8.

Sean has given you some good advice on known issues.

Another common failure point is the ignition switch, the electrical switch mounted on the end of the ignition lock barrel, which can be tested with an ohmmeter at its electrical connector inside the steering wheel cowl.

I haven't studied the schematic, but off the top of my head another possibility could be one of the Ignition Positive Relays. There's one in the left heelboard fuse box, and the other in the engine compartment fuse box.

If you don't have the X308 Electrical Guide for your 1999, it can be downloaded here:

http://www.jagrepair.com/images/Auto.../jagxj1999.pdf


Our fellow member avt007, (Rob), has created an excellent Electrical Troubleshooting guide for the X308 available at this link:

http://www.mediafire.com/view/j4irvg...v._2.2.pdf%22/


Also, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post an introduction so we can give you a proper welcome and so we can know a little bit about you and your Jag.

Cheers,

Don