For some months now my 1994 XJ40 has been in the driveway in park just making the ding ding ding when I turn on the ignition...
It started with the break lights, when I put on the brakes the voltmeter would go to zero, and come back up (might have been the pump). Then it started cutting out intermittently. This over a few days. After a couple of times sitting by the road waiting I put it in the driveway and... Ding Ding Ding.... not much else.No instruments, no starter, a few relays clicking over. I started looking over the wiring diagrams, because a few things were working (right side marker lights, not left Door locks, not trunk, Right side windows, not left. Common trait? the Left fuse block items didn't work, the right fuse block items did. Today I detached the left fuse block and checked the main power cable coming in, nope, no power. So, I'm a curious guy and I want my jaguar back in action, so I took a jumper cable and ran it from the positive jumper terminal under the hood to the fuse block cable where it comes into the block. long story got short, everything came to life and I started the car. I shut it right off due to the weirdness of the set up and having the alternator only half installed. Now, finally I get to my question. Where can I access the jumper terminal end of that cable (according to my diagrams it draws it's power there) and failing that, can I jump from the starter terminal to the fuse block? whatcha think? lets face it this car cost me a grand and I'm not about to take the entire dash out for this fix (by the way there are lots of holes in the floor I can fit a big cable through).
Thanks for looking at this, hope somone else has run this wire or reconected it or whatever needs doing, then again, hope it wasn't you because I'm betting it takes the little peoples' electric genious team to get to it from anywhere.

 

Hi unhooked59,

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

The other end of the large power cable that supplies the Left Fuse Box attaches to the Jump Starting Terminal, which is conveniently located on the Firewall/Bulkhead to the right of the engine (as viewed from the driver's seat). Corrosion or looseness of the terminal is a common cause of various hard-to-diagnose electrical gremlins. You can also check the continuity between the two ends of the cable that feeds the Left Fuse Box.

The photos below will help you locate and clean the Jump Starting Terminal:

Welcome to Jag-lovers - Members Photo Viewing Page


If you know how to solder, now would be a great time to service your Left Fuse Box while you have it out, since starved or cold solder joints in the fuse boxes is another very common cause of gremlins:

http://www.jag-lovers.org/snaps/snap...?id=1388005692


It's also worthwhile to clean your other battery power connections, as well as your ground points:

http://www.jag-lovers.org/snaps/snap...?id=1388131684
http://www.jag-lovers.org/snaps/snap...?id=1388098570
http://www.jag-lovers.org/snaps/snap...?id=1388091656
http://www.jag-lovers.org/snaps/snap...?id=1388071677
http://www.jag-lovers.org/snaps/snap...?id=1388068907
http://www.jag-lovers.org/snaps/snap...?id=1388009913


Please let us know how it goes.

Cheers,

Don

 

Looking in the footwell and at all the ac and cpu action to remove...I think I'm going to buy a four foot ground cable and work from the starter terminal or from the engine side of the jump start terminal, really just too much pulling apart for too little gain! Thank you for the links though, really helped me make that decision!

 

P.S. I just realized I should have mentioned that the Left Fuse Box cable attaches to the firewall post inside the passenger cabin - the post passes from the passenger cabin through the firewall into the engine compartment. You will need to remove the passenger side knee bolster and displace some of the electrical components to access the firewall stud from the interior. I'm not positive, but on the '94 you may also need to remove or displace the passenger side airbag (our '93 has a glove box - no airbag). It's really not nearly as difficult or time consuming as you may imagine.

Here are some more photos that may help:

Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page


Cheers,

Don

 

good news! I found the break in the line, it is at the pos battery terminal post (so labeled ) in the drivers footwell. the pos wire separated from the end. Lots of corrosion, probably related to the holes in the floorboard letting in moisture and salt which leaced up through the carpet and killed the connection end. going to the electronics store now to see if I can source a new end I can put on without routing a whole new cable. not sure why there is a post there at all, instead of a direct cable from a to b, but theres one on the right side too, might have a look at that when I get this patched.

 

soldered on a new end to the cable and all is well, had to reinstall the alternator, that was hard to line up, and the smog pump, and now I can't find the code to my radio, but hey, the car works!

 

Finding your code will be the best option, but if you just can't locate it, here's a trade secret courtesy of paulajayne at the U.K. XJ40 forum:


To recode the Jag Alpine Radio AJ 9200 R the onboard jumpers (they can be seen hidden under the label - run your finger over the label and push the soft spot, this will create an oblong hole) need to be changed.

They need to be all bridged - so out with a small soldering iron and a small cross point driver.

First remove the top cover to reveal the cassette deck. There are two screws that need to be removed before removing the other side; they match up to very obvious points on the base cover.

Once they are out remove the four base cover screws and then the cover.

Identify the jumpers that were visible through the hole and solder any unsoldered pairs.

Check with a multi-meter after soldering.

Reassemble - put in car and when CODE is requested enter 6543 - Radio should now go.


Cheers,

Don

 

that is a great tip! I hope after I have cleaned out all the debris of the gremlin hunt I will be able to find the card that came with the car (for the radio code) but what a fantastic second choice! thank you so much!