Hello everyone,

I am trying to diagnose what may be the issue on my 2002 Jaguar S-Type as the battery keeps dying every now and then, I changed the battery recently as I thought it was the problem unfortunately it didn't solve it, I did a battery leakage test but it turned out to be fine.

Note that sometime the car works for several days with no issues.

 

What sort of test did you do exactly?

Look up threads on here on quiescent current as they are what you need.

 

Here you go:

https://www.jaguarforums.com/forum/s...-drain-123535/

 

I don't know what the exact name is but here is what I did:
Disconnected the negative terminal while keeping the positive connected, took a voltmeter put one end on the negative terminal and checked each fuse that I could reach to see if it would drain while the car is off.

 

Thank you I will check it out

 

In the first month and a half of purchasing the new battery the car worked with no issues but then started to drain the battery

 

I checked it and in the part that he talked about his friend's car, he said that even after the new battery was placed the same problem kept happening but that is not what happened to me, what might be the cause.

 

That won't work. Worse, it can make things look good that aren't and bad that aren't. Follow the threads mentioned.

 

That wont work, you need an ammeter. A multi-meter wired in series using the amperage lead connections is needed. You will need to be careful not to have anything on the car cycle as you add this (you want a low current range to check for current draw). If something like the fuel pump or central locking cycle, you'll blow the meter up (most meters will have an unfused 10amp setting).

 

As advised, you will do well to follow a systematic approach, as set out in our write-up which JagV8 pointed to and Karl has linked. Read all the posts because there are several handy hints beyond my initial posts.

Cheers and best wishes,

 

Had a similar issue with my 02 v8. Figured it was the key flap staying open when removing the key causing the stereo (aftermarket) to stay on. I rarely drive it anymore so I installed a kill switch on the battery. Pretty cool device but if you don’t have a keyhole on your trunk I would not advise it unless you know how to jump power from the engine area.

 

This is a common topic,
My problem was solved when I realized I did not drive the vehicle as a daily driver. This caused the same battery issue as you are experiencing.
These S Types need to be run and as two mechanics told me run as they were meant to run - aggressively. I did not really understand and could not appreciate what they really were trying to get at.

When the car sits it is slowing drawing the battery down as there are several little devices slowly drawing down the power. I was getting all sorts of gremlin messages (fault codes) on my display and often the
car went into creep mode. The battery tested fine, the car would start, but the voltage was probably borderline, like 12 Volts instead of 13 or so.

The reason these mechanics were saying to run the car often and fast was probably that the battery can not sustain its charge when sitting more than it is running.
My wife was stranded many times during these creep mode incidents. So she would not drive it.

I put my 2003 S Type R on a smart charger every time I park it in my garage or just outside of the garage and have not had any problems since. On this forum I see folks chasing and trying troubleshoot these fault codes endlessly. When the codes are cleared and they don't return (for awhile) what might that indicate? Might be the battery voltage is borderlne as it starts the car but cannot support all the electronic gizmos.

I am not a mechanic nor electrically technically inclined, but I do respond to my experiencial evidence and am now really pleased that I no longer have to worry about those Codes and creep mode occurrences.

Cheers to all.

 

Smart charger can help cover up a fault or as stated can be good for a very low usage car.

To check for the fault case follow topics already highlighted.

You should be fine parking e.g. at an airport for 2-3 weeks, if not something's wrong.