Hi everyone!

I've already used the search feature about this and found lots of posts about this apparently common problem but most don't offer many solutions. Seems either some people don't report back with what their solution was or maybe their problem never got fixed.
Some background:
I just bought this thing last week, a BRG/Tan '97 XK8 convertible with 98k miles for about $5000. It seems to have been sitting a long time previously. All 4 tires are dry rotted and of course failed VA inspection. The parking brake "relay lever" pivot was froze with the brake on. I was able to fix that no problem. Everything else seems to be in decent shape otherwise considering. Except for one thing.
Got a new battery for it but it goes dead after a couple days unless you unhook it. I got out the trusty ammeter and with the car locked there is a steady 2 amp draw and with the car unlocked there is a steady 3.5 amp draw. No wonder the battery goes dead so fast. Removing fuses one by one from each fuse box local seemed to have little effect. I am guess the problem must be the SLCM from what info I have found in other threads. And I know I have to find a replacement with the same model and programming code number. The weird thing is that the module seems to be working properly otherwise. Both FOBs work, all the lights and the top works, door and trunk lock all work.
I was just wondering if anyone had any other ideas or things I should be looking for. And yes the little flap on the ignition key hole works and I cannot find any bulbs staying lit anywhere.
Any insight or help will be greatly appreciated. My project for the weekend is to pull a valve cover and check the chain tensioner.
The front tires in addition to be rotted are work more on the insides so I need to get the alignment checked before I chew up a new set of tires.


Dave

 

The SCLM is powered by a 10a fuse in #10 position in the trunk. Did removing that fuse kill the current draw? Two to three amps is something significant like a light bulb. May I suggest that you go through the owners manual list of features and functions and see if everything works . . . or doesn't work.

. . . and welcome to the wonderful world of Jaguar!

 

Hi.

Nice looking car.
Some members with auto headlights function have reported leaving the switch in auto will drain the battery.
A car not driven for a long period will sometimes have different electrical gremlins. Driving the car will often correct the problems.
Up to 60 min required for all modules to go to "sleep". After 72 hrs an even deeper mode.

 

I just went and pulled that fuse again to make sure I didn't manage to miss that one before. Pulling it makes no difference at all.
The weird thing is that the current draw is a steady 2 amps with everything locked BUT jumps to 3.5 amps and stays there if you unlock everything either with the key or the FOBs. So unlocking the doors makes it worse for some reason. Thats why I suspected the SLCM.
I can't seem to find anything that doesn't work which is surprising on any Jag. I don't hear any fans running and when I checked it at night I didn't see any lights on anywhere. 2 -3.5 amps is a lot of draw even for a light bulb (unless its a headlamp). For instance, the 2 trunk lamps only add 0.38 amp to the draw if I hook them back up.

I've owned several Jags before but this is my first one in 10 years and by far the newest one. I'll probably live to regret this one


Dave

 

Welcome. Nice find and looks like it got the right owner. Lots of help here.

Wayne

 

just a WAY out there idea, but it happened to me once - the CD player never shut off. It was hard-wired to a 12v source ... kids .............

 

This one doesn't have the auto headlight feature. I've had the car for less than 2 weeks though I knew of it for several months but they wanted to much for it at first and finally came down. The only 2 things it failed on inspection were the tires and the frozen parking brake (which I have since fixed). I still haven't put tires on it yet because I am to broke after just buying this thing. I have only driven it about 30 miles (with no safety sticker I was to paranoid to go further). It drove very nice with no codes or errors. Brakes all look as new. The drivers seat needs work but the rest of the interior is real clean and it came with all 3 keys, 2 FOBS, the manual pack and the top down cover.
I bought this because a teenager ran a light and totaled my '87 Alfa Spider that I owned since '90 and I found it was much cheaper to get an XK8 than to replace the Alfa! And the insurance company wouldn't pay me enough to find another Alfa in the same shape mine was.
I don't even own a regular car. I used to drive a '58 XK150 as my daily driver for 11 years. Can't afford something like that anymore.


Dave

 

A couple more pics. I had to make up a front license plate adapter as VA is one of the few front plate states left. I did it so its reversible and no holes drilled at all.


Dave

 

Three amps is a large discharge, have the alternator diodes checked, they can short to ground, the fuses you pulled won't stop that draw. You can disconnect the alternator lead to battery or use an amp-meter.
If you are in the Vienna, Va area I have a clamp-on meter to check the circuit draw.
Good luck

 

Good call!

 

The amplifier and CD player have been know to not sleep properly, though 2A might be a bit high for that, if you have the sound system with CD and amplifier in the boot/trunk. Think it is wired via an inline fuse.

 

I'll check that out in the morning. If any of the diodes are shorted it should also show up loading the alternator down while charging as its output will be limited.

Nice to see someone else here from VA. I am in Damnville, I mean Danville.


Dave

 

Well I found part of the problem -

First I undid the cable from the alternator at the "High Power Protection Module" (fancy name for 2 fuse links in a plastic box) in the trunk. There was still a 2 amp drain so its not the alternator.

I found 2 electrical connectors and a vacuum line tied up near the battery "+" terminal. None were hooked to anything. And there is nothing to hook them to. The vacuum line comes through a grommet in the trunk floor. and after a foot it just ends not hooked to anything. All I can figure is these must go to "features" my car doesn't have.

While looking for things they may have hooked to I removed the right hand carpeted cover that covers the top pump and CD Player etc.

Right off I noticed the cabling to the power amp had been cut and a new plug spliced onto the wires that plugged into a non original power amp. And you guessed it someone wired the damn thing so not only is it on all the time but its not FUSED. It should go to fuse F9 but its B+ has been hardwired in somewhere else. Unplugged that sucker and the 2 amp draw dropped down to 0.5 amp and then after a few minutes that dropped to 0.28 amos (280ma).
So now I know the source of the bulk of the 2 amp sraw but now the problem is whats causing the 280ma draw?

Dave

 

told yah - kids do the damndest wiring - its all fixable, though.

 

Its fixed but I just didn't know it!

It first will draw 0.5 amps and then after a few minutes its drops to 280ma. BUT after about 30 minutes it drops to around 35ma and stays there. I let it do this cycle several times and it appears to be the normal draw sequence as it starts sleeping different things.
I was going to put an all new stereo setup in it anyways so this will just motivate me to get it done sooner.



Dave

 

Just a quick comment on the loose vacuum line. That isn't a vacuum line it is the vent hose for the battery. If the battery you have in the trunk doesn't have a vent tube then get rid of it and get one thats vented. You don't want the battery fumes in the trunk. Both my XK8 and XJ8 have vented battery connect to that tube.

 

Thanks, I'll take a look at the battery tomorrow as its raining now...


Dave

 

Hi again.

Typical drain 60 min. after locking the vehicle is approx. 30 ma. (Battery care manual)
And yes, the battery vent tube is important.

 

Its an Interstate 49-C battery and it does have a vent hole. And of course its where the threaded post for the hold-down bracket blocks it so I think I can loosen it and slide the battery over enough to get to it. Now the problem is I need the "elbow" that would have come with the battery to plug the end of the hose into. Going to call some places that sell batteries and see if I can get that without buying a new battery.


Dave

 

Installed a Interstate 49C battery in my car, it came with a vent kit(tubing and elbow insert), I had to run a drill to open the vent hole.