I suspected a slight battery drain on my 99 XK8 so I did a test today and found that after an hour I had a .1 to .2 amp drain. Now according to the Jaguar chart I should have around a 30ma drain and the .1a equates to 100ma so it appears I have an issue to attend to.

I plan to start checking further but would like to know of any issues others might have come across in the past. I do not want to spend the entire day on this so any help on this would be greatly appreciated.

 

Hello Gus:
(.1a) is 100ma. (typo?)
Anyway, I would check the ignition key door flap first. Somehow, I think that although there has been much conversation on the forum about this, I have not hit on the root cause for my variations in drain time.
Maybe it will show up on this thread.

 

Hi Gus,
Did you keep the LED front markers? If you still have them, do they eventually go completely out?
Just a thought:- would tell you at least whether the car falls into sleep mode or not.

Other than that, DaveInVA had an issue with the audio amp, although I think the drain was higher than you're experiencing.


Mike

 

Thanks! I corrected my typo.. The key flap was first on my list but thanks for bringing it up. As for the bulbs I had not installed them yet but was planning to. I held off because of my suspicion of a power drain and wanted to check it first. As for Dave do you recall if that was an aftermarket unit?

I dread going from one fuse to another.

 

Hi Gus,
Dave's was the stock HK unit. I've just checked the post, tho' and he reported a 1-2A drain:
https://www.jaguarforums.com/forum/x...3/#post1087374

Loved his 'spoonerism'

The LEDs will be fine - think about it: they can't draw any more than the incandescents they replace.

Mike

 

Thanks the amplifier is now on my list..

 

Gus, this is a thought I had about tackling you problem. Disconnect the power to one fuse box at a time. Then see if you still have the power drain. If the power drain goes away that will be the box that has the drain. Then it will narrow down your search to the circuits in that box. It will save time from having to check each fuse in the car.

I'm not nearly up on the electronics on these cars as you are. I don't know if disconnecting one box at a time will effect other electronics. If it is not wise to do it this way please correct me. I'm still learning about what can and can't be done on these cars.

 

With a good meter you can check the Volts (yes!) across each fuse. Well, millivolts. (google for more info)

Each fuse normally has its contacts exposed at the top.

This way means you don't pull fuses or the like, so don't mess with waking up / annoying modules.

Your drain is small so you will have a very small voltage drop...

 

Thanks! I did a little checking today and found the amp meter I was using was a little off so I will be at it again tomorrow. I have a good volt meter and will see what I come up with.

Walked away from it today and changed the differential oil in my S-Type instead.

 

Worth watching .

 

Yes I have seen this video. Good stuff!!

 

The main problem with pulling fuses is they start and stop circuits that need to be unmolested for 30-45 minutes in order to go into sleep mode. Otherwise you are measuring current that would eventually shut itself down. The best way I found to circumvent this issue is to measure voltage drop across the fuse.

So with the doors, hood and trunk open, and after the system had gone to sleep, I used a voltage drop test. This way the system is not energized by opening and closing circuits with the pulling and reinsertion of the fuses. Plus it is a much faster way of locating excessive current flow. Remember, the voltage drop is a relative value, not the actual amperage; however, it is correlated to the amount of current.

There were three or four fuses that appeared suspect. I then reverted to pulling these fuses to confirm parasitic drain(s).

I found a major draw on the body processor module, (#5 DS door panel) a 15 amp circuit. Went from 1.200 amps down to 0.040 amps. Still waiting on pulling the glove box and retrieving suspect module.

For now I am using a charger to keep things topped off until I get round tuit.

 

Great if this worked for you, but not on either of my admittedly later cars (MY04 XK8 and MY07 S-Type) nor on others tested for confirmation. While I see great merit in the millivolt measurement across fuses advocated by [JagV8] as a means of MINIMIZING much of the time consumed "pulling fuses", the conditions that Jaguar lays down for attaining the "sleep" condition specifically call for shutting all windows and doors and waiting for the time to expire. IIRC, when assembling the QCD How To in the Stickies, it was the PATS that otherwise disallowed "sleep" . . . and if you inhibit that "sleep", it makes any reading meaningless at best, or worse, gives a misleading diagnosis.

This might be a moot point if one is chasing down a QCD of 1-2 Amps, and that is not uncommon in some of the bodges I have unravelled. Such a QCD is some 30-60 times the permissible level. But Gus is chasing down a QCD barely 3 times the maximum level, so let's do it "according to the book".

My experience of using the Power Distribution wiring diagrams to pull the feed to major junction boxes or fuse boxes, one at a time as suggested, provides a not unacceptable time taken to isolate from which box the culprit circuit arises. This, coupled with a lifetime of finding that 90% of these QCD issues flow from bodged DIY wiring mods around audio, instrumentation and lighting circuits, soon runs the correct culprit down.

Cheers,

Ken

 

Well I found the problem and it was my battery as I suspected.

My first test I was using a load meter that needed a new battery and that accounted for my bad reading. I changed the meter and was able to get an accurate reading. The battery was purchased Feb 2015 and thought I was going force the issue when I returned it however, it was not an issue and they replaced it without question.

My initial reading was 1.01a 12.14v and after an hour it went to .01a 12.31v. Now before I started testing I charged the battery overnight so it had a full charge to start with. What I noticed when I started was the voltage was 12.4 with an amp reading of only 1.01a and as the load decreased to .01 the voltage went up to 12.31. I was glad to see that my parasitic load had dropped to 10ma well under the Jaguar recommendation of <30ma.

Thanks for all the input.

 

Great work Gus, and thanks for the the updated data.
Re-checked 2 of my Jags yesterday . . . 12.8V and 12ma (XK8) . . . 12.95V and 16ma (S-Type).
Voltages comfortably above threshold of 12.6V and . . .
As you say . . . QCDs well below <30ma Jag spec.

Cheers,

Ken

 

I have been trying to track down a parasitic drain on my car for sometime. After reading about the amplifier, I crawled inside my trunk with a flashlight and felt around the amplifier and other components below the hydraulic pump. Not only have I found hydraulic fluid stains directly above the vents on the amp showing fluid made it inside. I felt around the wire harnesses, for bound wires, and the twisted wire pairs on the back were fine, but a set of twisted wires were routed around the inside sharp edged shelf the components sit on, and the wires are very tightly bound against these sharp edges. I also have a dead speaker behind the drives seat, no sound, static, nothing.

As my drain is significant, if I do not drive the car for a few days it will be completely dead, I would like to unplug the power from the amplifier until I can get in there and pull the whole stack out, I do not care about listening to the radio as much as my car starting at this point.

Is there a single plug or cable to unplug the amplifier and stop it draining the battery? If so where is it located? Is it the round ended grey cable at the back of the amp, or other bundles of twisted wire pairs plugged into the side of the amp, not the twisted wires at the back with the grey cable, that are being cut into by the metal shelf's sharp edges, or another wire somewhere else that supplies the power to the amplifier, that is no longer shutting off with the car, and draining the battery from a full charge of ~12.99VDC down to ~2.48VDC in ~18 hours?

Thanks in advance.

 

I have not done this but from what I have been told you could take a volt/amp meter and put it on amp and test across the top of each fuse. First open the trunk and hood and let the car sit for a half hour or so. You will know when the trunk lights go out. Then test across the top of each fuse with the amp meter and see what you come up with. When you do this see if you get a reading on any of the fuses and jot the fuse number down. I am not sure you will get a true reading but it is worth a try. The only 2 fuse boxes you will not be able to check are the 2 in the door jams. Let us know what you come up with.

 

When my amp died it would kill the battery overnight. One giveaway was that the amp was warm to the touch even after the car hadn't been used for hours. Best way to disable it is to pull the fuse for it in the trunk fuse box. If the amp is the problem take a meter that can do amps and set it to the highest amp scale (such as 20 amps) and probe the 2 contacts where the fuse was. Mine was drawing nearly 2 amps constantly which explained why the battery died so fast. I was able to repair the amp, was a bad output IC.


Dave

 

Thanks, I wish there was a power cable directly to the amp that can be pulled to de-energize the amp until it warms up outside and I can take care of it properly. 1.5-2.0 amps is my draw, and will kill my battery down to 2.48VDC after ~18 hours, I did not do the pin out on the fuses test. An 'old timer' at the 'Area' taught me how to figure out a draw by knowing the voltage of the battery after it was last driven as a baseline, then take the current reading and blah, blah, cannot remember, forgot the steps, but can somehow do it in my head even though I do not understand the 'math' behind it and how I keep coming up with the correct value. I can do this with Algebra and higher mathematics as well, damn if I understand any of it, or can show my work because I cannot most of the time, but I will know the right answer by just studying the equation, jinkies.

I already know it is the amp., it is quite obvious that something is wrong with it with my dead channel, and by following the pool of hydraulic fluid directly into the amp. is a dead giveaway, and it is warm in 30 degree weather without the car being run, so I know. This car had been serviced heavily over a few minor problems that I would have fixed myself, but then I would not have this car, as I suspect the previous owner did not do their repairs because EVERY problem the car has, is coincidentally in the same area warranty and/or recall work had been performed. This is evident as I got the list of recall/warranty work and use it as a guide to correct every area the tech's were in, so far this is the last area! They repaired the antenna last, and it was probably the final straw when the battery started dying on them as the po's traded it in on a new XK.

I believe this is how the one set of twisted wires ended up routed tightly around the inner sharp edges of the shelf the components set on. It looks like they already put it all back together, then found the wires, and were like 'F' this I am not taking this pos back apart', and just crammed the wires where ever they could get them to be close enough to plug back in and the wires are bound and the insulation has been compromised, and the wire pairs are constantly in contact with metal.

So Please, Please, Please; is there a single cable that provides power to the amplifier only, that I can pull in the mean time?, Please. I just want to stop the drain for now, I do not care about listening to the radio.

 

Your car has a different amp than my '97 had. If yours is the LNF4170AA then removing the large rectangular plug that goes into the white connector should kill the power to it. the 2 round connectors are for the cd and head unit. However if a wire in the cable going to that connector is snagged against sharp metal that could still cause a short. The easiest thing would be to simply pull the fuse in the trunk fuse box, Should be a 30 amp fuse in position #18 in the trunk box.



Dave