My 99' super v8 has recently had a new battery, that seems to be draining for some reason. No lights etc have been left on, but the battery goes flat if left for a couple of days. Any ideas what may be causing this?

 

If it is dying within a couple of days then most likely you have a parasitic drain going on. One of the most frequent ones is the small door that must close over the ignition switch when the key is removed. It is the easiest ones to cure with a little spray lube silicone or wd-40 on the switch. If the door is closing the I would recommend following the link below and go to post #4. It is a search procedure that I found and works surprisingly efficient and easy.

https://www.jaguarforums.com/forum/x...estion-207312/

 

Thankyou very much for the response, i'll give that a try tonight

 

posted in error and cancelled

 

Make sure the glove box is closed. Seems the left side sometimes does not latch correctly and the light stays on.

 

Make sure your trunk light is going out when it's closed. Just put your phone
on camera insert the phone where it can see the light and close the lid, Then
you can tell it that is the culprit.

 

If it is not a light that won't go out and you haven't found the source yet, I had a similar issue with the microswitch in the driver's door latch three years ago just sucking the life out of a battery. I got a used, cleaned and tested replacement which my shop put in for me. I cannot find the receipt, but I think I bought it from maybe JagBits in Michigan and it was shipped from a place in California. It showed at my East Coast house something like 38 hours after I pushed the button on the order. I believe I was getting an intermittent "door not latched" signal on the dash.

 

Just my own 2 cents, but I wouldn't recommend wd-40 or any other wet lubricant in any key cylinder. Dry graphite lubricant only in the key cylinder...ignition, door and trunk.

Incidentally, if you pick some up, I recommend you do all the key cylinders on the car periodically AND then exercise them with the key. You never know if your remote might crap out or your battery dies and you can't get into the car with an electronic method. Can't count how many times I've seen owners with a dead battery complaining about Jag engineers not putting a mechanical lock on the trunk lid to get at a flat battery when the actual problem is those same owners never test the key cylinder to make sure it works and will open the trunk. Had a long, drawn out discussion on Facebook with a frustrated owner who insisted he knew all about Jags and that the trunk lock was in fact only electronic and the key cylinder won't do anything and thats why his key won't turn...because Jag engineers are stupid. Turns out after a couple days of back and forth, it wasn't the Jag engineering team's fault.

 

I had a 2-3 day battery life on my 2000 XJR that wasn't one of the simple fixes like a light staying on. Post back if it wasn't one of the simple options.

It's not difficult to get to the bottom of the issue if you have a multimeter, just time consuming as it typically takes 30 minutes for the individual systems to enter sleep mode. I ended up replacing controllers for seats, doors, security and BCM with incremental benefits each time tarting with the biggest current draws and working my way down till the problem was solved. It was surprisingly not that expensive to do either, ebay is your friend. Keep in mind the newest x308s have 20 year old electronics that were designed many years before that. 20 years of heat cycles takes a toll, jump starts are a problem too.

-Mike