Hello!

Any common areas on our cars to check for a battery drain? Battery and alternator both test out fine. The battery is draining to no-start condition in like 36hrs of not driving.

Thanks!

 

oh my god me too! my 96XJR has the same thing, huge battery drain. Battery flat dead after a week of not driving. I been meaning to find out where but did't get the chance since the car is still in storage n stuff. I guess its too hard to say but i too would like to know the common areas so i don't have to pull fuses one by one with multimeter

 

Is the clock on the radio supposed to stay on when the car is off and the key is out?

 

yes i believe so, my clock stays on even when key is out. the clock takes so little power to run it surely would not drain out the battery

 

Mine, too!! I keep mine plugged into a trickle charger all the time.

I've replaced alternator and battery. Now the long arduous task of metering the battery as I pull each fuse, one at at time to see which circuit is draining the battery.

 

Check the trunk light switch

 

The light goes out after awhile, but the battery still drains.

I'll be doing this...

 

Guys,
There is no clock on the original X300 stereo, so if you have a clock on your stereo which is still on, it is non original, and might be a place to start checking. Original X300 stereo would be off with key removed.

 

There is a constant power lead to the original radio to store saved radio stations that modern radios would use to keep a clock running - not that something like that would drain a battery overnight.

 

This is incorrect, at least on US cars. It's a OEM Jaguar head unit with a clock. Can anyone tell me if their clocks stay on(visible) with the ignition key off?

 

Craighead,
do you have a picture of the headunit? Is the clock in the centre panel deleted on US cars, or do you have it as well? The reason I ask is that the clock display in the X300 dash is famously unreliable, and having had mine refurbished a couple of years ago, it is on the way out again. If there is an OEM head unit with a clock, that might be a better way forward.

 

The original stereo does not have a clock. The display window on the head unit shows the radio station ID when switched on, not the clock. The clock is positioned above the head unit, centered between the central locking button and the hazard lights button.

This is a pic of mine (totally original) with ignition off, showing the clock is always on. The continuous clock is not enough to cause the abnormal battery drain.

 

I had a similar slow ,mysterious, battery drain in my '95 XJR. The battery would go down in a few days unless I drove the car. I have a complete factory manual including the electrical system. Boy! Does that car ever have a complex system. I got far more familiar than I ever wanted to be with that system! I pulled every fuse, one at a time and checked for a drain current. The timer on the trunk light complicated matters. What I found was a drain current larger than the usual 30 milliamp or so "keep alive" current. The drain went away when I disconnected the fuse to Body Control Module.

That was no help because almost everything goes through that module, Eventually I started suspecting the part of the ignition switch which detects if the key is left in when you open the driver's door. Before trying to replace tha entire switch, I squirted some Triflow lock oil into the ignition lock and exercised the lock by inserting and turning the key many times. After a day of sitting, the drain current disappeared and has not come back.

You might try getting the TriFlow oil ( recommended by my locksmith) and lubing the lock Like I did. To see if you have fixed it, first put an ammeter between one of the battery cables and the battery terminal. After the trunk light turns off you should be able to read the current drain. If the drain is 80 milliamps or more, that is the reason you battery is going flat. Now try the lock lube like I did, give the oil a day or two to loosen up the switch and re-check the current drain. If it has gone down, you're good to go. If not you may have to monitor the current drain while pulling fuses one at a time to get an idea where the drain is located. It can get complicated.

Good luck!

 

300holst,

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

Thanks for sharing your successful diagnosis and resolution of the battery drain in your car. Hopefully that will work for other owners.

Since we're a friendly group, 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 learn something about you and your Jaguar.

Cheers,

Don

 

I have a $20 5.5 watt solar charger in my parcel shelf that maintains everything nicely, never have to think about it even with couple of days of rain or extremely cold weather.

 

That is a great idea, but doesn't help in the garage.

 

Where is the BCM fuse? Please don't make me read through the manual.

 

I have it as trunk fuse no. 5. Should be a 10 amp fuse. Remember that many circuits go through this module. When I found the leakage current going through the BCM, I replaced it with one from Ebay with no improvement. The problem was the ignition switch as I said earlier. I would start with the ignition switch since that is easy to do. If lubing it doesn't fix the problem, you will have to do a systematic check one fuse at a time.
Good luck.

 

Before I order the Triflow lock oil, I want to see if this is the culprit.