You are absolutely right. The XK8's computers sense when the key is inserted in the ignition lock, and may never fully go to 'sleep mode' for minimum current drain.

 

That's a pretty healthy drain though but it would still take 400 hours or more than 2 weeks to flatten a 100Ah battery.
Just out of interest would the OP take a reading with the key out of the ignition and the car unlocked?
You need to wait a couple of minutes after turning off the ignition because the aircon stays on to allow it to shut down properly.

 

Definitely, locking the doors has taken care of the problem. It may well be there is a problem with the alarm or some other power down component but it definitely is not worth the effort to find out.

Although I have not taken any readings both leaving the key in the ignition and the doors unlocked cause drain in their own part.

I will try and take reading and post here, just need to find a small 12V battery to do a parallel connection while I am hooking the tester up so I will not loose memory in various components.

 

Hello All,
Let's make that 3 with this same problem.
I ran the multimeter, 10A, is in series. After dome lights are on it reads 2.2A, then drops to .62A after the domes go out. About 5 minutes later the draw is ~.45A and stays there.

Every fuse has been yanked and all relays have been pulled while my better 1/2 watched the ammeter. Nothing dropped the amps. Battery dies after 3 days. The only electrical items replaced were the horns and the instr. dash for the Nav system. White XKR provided the wiring harness..(BTW White...they work great...good job!!)

Any other ideas?
Thanks
Bill

 

Hi BIll-
Have you checked yet for a stuck 'window' in the front of the ignition switch keyhole?

And thanks, glad the nav to 3-gauge conversion went well!

 

Yes Sir! checked the little door with a scribe and it opens and closes and does nothing to the amps. I'm running about .44A-.48A 24/7 when not running. Started out last night with ~12.5VDC and this AM it was about 11.4VAC, so she is running down fast.

Without an terminals hooked up and fully charged I see a difference ~
-.1Volts over a 24 hr. period if that much.

Any thoughts?

Thanks,
Bill

 

This happened to my 1999 XK8 this past week! Drove it about 20 miles, parked it, didn't set the security alarm when I got out. Battery drained to zip! Recharged the battery, same thing next day. Checked everything out, lights etc, all okay. Charged the battery again and noticed that the lights didn't go out in the car when I shut the door! Locked the car with the fob and they went out. Battery was fine in the morning, drove the car no problems. Will make sure I always set the alarm from now on.

 

Gent's , Ladies,
Good morning!
Found the fuse block, passenger door(fascia). Disconnected the hot wire and looped in the ammeter, 0.5A reading after 2 hours. This is the only place where the voltage drop is. The other 4 blocks are 0.0A. Removed all 18 fuses and the relay. Still a .49A reading.

Anybody have any thoughts on this one before I go and remove the fuse block and look for crossed wires?

Thanks,

Bill

 

Gents, I've pulled every damned fuse in the 2000 XK8 and finally got one that appears to cause the battery drain. It is fuse No. 15 in the Fascia fuse box, driver's side. It is a 25 fuse and controls the driver's door control module and transit relay(what ever that is).
Replace the module? Your thought's please. What is the transit relay?
Thanks,
Bill

 

I can see this post remained unanswered. I am also having issues with battery drainage. Did you ever find this transit relay purpose and where the drainage came from?

Thanks,
Claude

 

Search shows the transit relay is only fitted during transit, is removed by ... etc.

Current drains tend to be car-specific and - again - Search shows how to find & fix them.

 

See the information in this pdf

 

Thanks, yeah I guess we all need to go through our own experience. I need to be sure to lock doors, which sometimes I don´t
Third Battery drained, and ruined.
Thanks again.

Claude

 

Thanks, understood makes no sense. We all recieved cars without transit relay activated then.