The wonders of S-Type electrics
Discussion
Eveer since I got my 2001 car almost four years ago, it's had Random Flat Battery Disease. This means that the car works perfectly normally for a period of anything between one day and six weeks, but will then drain its battery totally in 5-6 hours. By totally I mean even the door won't unlock, it's that dead. I deal with it by carrying a spare battery in the back and have become quite deft at swapping them over.
The problem is of course one of those 'we checked it and couldn't find anything' faults, but yesterday I got a clue (possibly).
Walking past the car after dark I noticed the immobiliser light wasn't flashing. Thinking I may have forgotten to lock it, I tried the door handle but the car was locked. Peering in to the cabin I noticed that the clock display was full on, and the satnav power lead in the lighter socket had its green LED lit. Hence the lighter socket and clock circuit were live and using power... (note that the satnav is a new addition last week, it's nothing to do with the problem)
I unlocked the car, put the key in the ignition and turned it on and then off, then closed the door and locked the car. This time the lights faded out after a few seconds and the immobiliser light started flashing as usual.
Are there any geniuses around who might be able to use this info to pin down the problem?
The most spectacular thing this car has done is lock me out with the engine running and my phone inside. I'm thinking of calling it 'Christine'...
The problem is of course one of those 'we checked it and couldn't find anything' faults, but yesterday I got a clue (possibly).
Walking past the car after dark I noticed the immobiliser light wasn't flashing. Thinking I may have forgotten to lock it, I tried the door handle but the car was locked. Peering in to the cabin I noticed that the clock display was full on, and the satnav power lead in the lighter socket had its green LED lit. Hence the lighter socket and clock circuit were live and using power... (note that the satnav is a new addition last week, it's nothing to do with the problem)
I unlocked the car, put the key in the ignition and turned it on and then off, then closed the door and locked the car. This time the lights faded out after a few seconds and the immobiliser light started flashing as usual.
Are there any geniuses around who might be able to use this info to pin down the problem?
The most spectacular thing this car has done is lock me out with the engine running and my phone inside. I'm thinking of calling it 'Christine'...
Erk, You'd have to find out where the trackers are normally installed (rear bumper, under seat, behind passenger dashboard etc) and have a look.
The only reason I mention it is because if the install has been botched, they have been known to cause intermittent problems and it wouldn't be outside of the realm of reason to suspect that it could be the issue.
That said, if the dealer has done a thorough job in checking for the drain, they would probably know if a tracker was present.
Personally, I would try to find a local auto-electrician and get them to have a look at it. They deal with stuff like this day in, day out.
The only reason I mention it is because if the install has been botched, they have been known to cause intermittent problems and it wouldn't be outside of the realm of reason to suspect that it could be the issue.
That said, if the dealer has done a thorough job in checking for the drain, they would probably know if a tracker was present.
Personally, I would try to find a local auto-electrician and get them to have a look at it. They deal with stuff like this day in, day out.
I've got a drain problem in an old BMW, instead of trying to sort it out I use one of these
www.batterybrain.co.uk
A wonderful little gadget, automatically cuts off the battery if the voltage drops too low and with a simple click of a remote control it all comes to life again with enough juice to start the car.
John.
www.batterybrain.co.uk
A wonderful little gadget, automatically cuts off the battery if the voltage drops too low and with a simple click of a remote control it all comes to life again with enough juice to start the car.
John.
steelej said:
I've got a drain problem in an old BMW, instead of trying to sort it out I use one of these
www.batterybrain.co.uk
A wonderful little gadget, automatically cuts off the battery if the voltage drops too low and with a simple click of a remote control it all comes to life again with enough juice to start the car.
John.
I've also got an old BMW (91 E30 318is) that had a drain problem. Wish i'd have known about that little contraption before forking out £300 to have it fixed. www.batterybrain.co.uk
A wonderful little gadget, automatically cuts off the battery if the voltage drops too low and with a simple click of a remote control it all comes to life again with enough juice to start the car.
John.
eldudereno said:
If you can find out the normal current useage from the owner of an identical car or info from the net you can just hook up your ammeter and pull all the fuses out in turn to see which is the offending circuit. It's a start at least.
The problem is that it's not constant. It only does it about once a month (sometimes twice in two days, sometimes it's OK for six weeks) so you could spend an awful lot of time testing it and finding nothing wrong.I'll certainly try the WD40 idea. What about squirting it straight in rather than via the key?
Hi, John.
Just to clarify, the cigar lighter was still live and the clock (part of the radio) ??.
All my Jaguar wiring diagrams 98-2004 are buried in my dads garage. Once I gain access, 2 or 3 weeks. I'll have a look at what circuit powers that stuff. And if it all comes down to one of them brown relays in the boot. I got a feeling the FEM and REM might have something (Front/Rear Electrinics Modules) to do with it then it gets really complicated.
If you notice it "Staying live" again. See if any of said relays are hot, they shouldn't be when the cars asleep.
I'm a bit too busy to have a look at if for you right now, And want to see the wiring diagram first anyway, I did have it on PDF and cant find it anywhere, so I get the paper coppies and get back to you.
PD.
My email is dead, I give you new Address soon, Post here or PM me.
Just to clarify, the cigar lighter was still live and the clock (part of the radio) ??.
All my Jaguar wiring diagrams 98-2004 are buried in my dads garage. Once I gain access, 2 or 3 weeks. I'll have a look at what circuit powers that stuff. And if it all comes down to one of them brown relays in the boot. I got a feeling the FEM and REM might have something (Front/Rear Electrinics Modules) to do with it then it gets really complicated.
If you notice it "Staying live" again. See if any of said relays are hot, they shouldn't be when the cars asleep.
I'm a bit too busy to have a look at if for you right now, And want to see the wiring diagram first anyway, I did have it on PDF and cant find it anywhere, so I get the paper coppies and get back to you.
PD.
My email is dead, I give you new Address soon, Post here or PM me.
Greetings TT! Tame Technician said:
Just to clarify, the cigar lighter was still live and the clock (part of the radio) ??.
Yes, and although the car door was locked, the red dashtop LED wasn't flashing, which is what made me suspicious. I now always check that it's flashing and the clock display is off before leaving the car.Tame Technician said:
All my Jaguar wiring diagrams 98-2004 are buried in my dads garage. Once I gain access, 2 or 3 weeks. I'll have a look at what circuit powers that stuff. And if it all comes down to one of them brown relays in the boot. I got a feeling the FEM and REM might have something (Front/Rear Electrinics Modules) to do with it then it gets really complicated.
I have a JTIS CD from eBay if that's any help?Tame Technician said:
If you notice it "Staying live" again. See if any of said relays are hot, they shouldn't be when the cars asleep.
Good logic, will do.Edited by Simpo Two on Thursday 24th July 23:13
I found the wiring diagram on old JTIS disc. Good thinkin. But not as much help as I thought.
The cigar lighter and radio are on very different circuits.
The "Key in" switch is wired only to the Instrument pack, and that works the immobiliser functions.
Given that the car only plays up from time to time, let see if we can replicate the symptoms.
To rule out the "KEY IN" switch within the ignition barrel, switch off car and leave key in, is the car in the same sate it was when you noticed the immobiliser light not flashing? Is the light flashing how is the clock looking?? If its different, then its not the key in switch. If it looks the same then try to lock the car with the remote, I don't think you can when it thinks the key is in there, but I'm not sure, let me know
The cigar lighter and radio are on very different circuits.
The "Key in" switch is wired only to the Instrument pack, and that works the immobiliser functions.
Given that the car only plays up from time to time, let see if we can replicate the symptoms.
To rule out the "KEY IN" switch within the ignition barrel, switch off car and leave key in, is the car in the same sate it was when you noticed the immobiliser light not flashing? Is the light flashing how is the clock looking?? If its different, then its not the key in switch. If it looks the same then try to lock the car with the remote, I don't think you can when it thinks the key is in there, but I'm not sure, let me know
Tame Technician said:
To rule out the "KEY IN" switch within the ignition barrel, switch off car and leave key in, is the car in the same sate it was when you noticed the immobiliser light not flashing? Is the light flashing how is the clock looking??
I've just been to the car, unlocked it and put the key in the ignition (but not turned). There was the usual 'zzpp' noise of electrics but the clock display did not come on. The red LED wasn't flashing but that's because I'd unlocked the car. So nothing unusual. Or should I switch the engine on first?The zzpp noise it the electric steering column lock coming off, but thats not important.
What you are trying to do is replicate the key in switch getting stuck, so you are switching off the car, but leaving the key in. Start the engine and switch off, leave the key in, and lock the door with the remote.
A) does it let you lock the door with the key in signal being braodcast on the network?
B) If it does lock the doors is the clock lit up and the immobiliser light not flashing? (is the car in the "failed state")
What you are trying to do is replicate the key in switch getting stuck, so you are switching off the car, but leaving the key in. Start the engine and switch off, leave the key in, and lock the door with the remote.
A) does it let you lock the door with the key in signal being braodcast on the network?
B) If it does lock the doors is the clock lit up and the immobiliser light not flashing? (is the car in the "failed state")
OK, results:
After engine switch-off and turning the key back to 0, the car would not lock from the inside using the fob. The clock display went off after a few seconds. The dash LED did not flash.
Removing the key and locking the car from the outside by remote in the usual way worked perfectly.
After engine switch-off and turning the key back to 0, the car would not lock from the inside using the fob. The clock display went off after a few seconds. The dash LED did not flash.
Removing the key and locking the car from the outside by remote in the usual way worked perfectly.
This confirms, The fault is nothing what so ever to do with the key in switch, (cos if the key in switch got stuck, you wouldnt have been able to lock the doors with the remote.
That would have been a nice easy fix.
Just keep an eye on it, When it failles again, check if the relays in the boot are hot.
That would have been a nice easy fix.
Just keep an eye on it, When it failles again, check if the relays in the boot are hot.
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