You have some kind of feedback going on there, that's probably why the motor doesn't want to quit right away when keyed off or the ignition disconnected. I've looked over the wiring diagram and have a couple of things to check out. First, there is a large usually white relay down low behind the LH fog light. You'll get to it from under the bumper. See if it has come off it's mounting and maybe hanging upside down and full of water & mung. Second, under the bonnet behind the RH headlights there are two rather large connectors, usually one white and one black. Take them apart and see if they are clean and free of corrosion. If nothing turns up there, I guess the real detective work begins.

Good luck!

 

Damn, you got one angry Jag there, dont you treat her NICE, of course you do, must be a redhead, hahaha.

That sounds like an ignition relay "sticking", and the MAIN one that comes to mind is that one you looked at in the RH under bonnet fuse block. They are, I believe, a STANDARD 5 pin relay, so a substitute would be a simple test, perhaps the relay for the horns from the LH fuse area under the bonnet, OR, get an assistant to pull that relay at the same time you turn the key off, process of elimination, as there are other "ignition relays" in the car as I listed before.

 

OK this time I am thinking something must be grounded out for sure.

1. Brand spanking new battery, checked at the store and reading max volts/amps.

2. Two days of sitting in the car with NOTHING on. The steering column only has the ignition portion plugged in.

3. I get in today, and low and behold not a thing works. Nothing will even come on, not the slightest click or even low glow from the lights, NOTHING.

I understand to start from the battery and move forward, but that's a lot of spaghetti. We are thinking it's pretty much something in the ignition system right? What do I follow to look through that system?

Any idea what could have gone from an occasional ground out problem to a full on battery killer?????

Thanks again guys.

 

at the risk of over-simplifying....your cable connections are clean where they join the new batt, aren't they?

 

Yes sir, I've even taken apart the large breakers on the positive terminal and polished them just to make sure. That is definitely not the issue. It is somewhere past the battery terminals I am sure.

 

OK, you got something serious going on, agreed.

My suggestion is get yourself a digital multi meter.

Plug the leads into the relevent sockets on the meter to read "amps DC". Most of these can handle 10amps, and that circuit in the meter is fused for protection anyhow.

Once the battery is recharged, leave the battery -ve cable off the battery, and connect the multi meter between the -ve battery post and the -ve battery cable. DO NOT turn on any high draw items, there is NO need, you are looking for amp draw whilst OFF. This will read the amps being drawn whilst the car is "sleeping" and 0.5amps is about normal. I would expect you to see about 5+ amps in your car, which indicates a leak to earth as you suspect.

Since everything is switched off, it is something to do with items that are +ve live at all times. Such as alternator +ve supply, relay +ve supply, interior lights, boot light, etc etc, basically anything in the car that has +ve supply not via a switch. This is a LOT, as you said, so I would look at the alternator, maybe a diode has gone "off" and is leaking to earth. Remove the battery cable from the alternator, insulate it well, and test again with the multi meter, and see if anything has changed, if so, problem maybe found, if not, keep going, one item at a time I am afraid, unless some shorted wire in that column area is obvious, which it appears from what you said, "all wires appear OK", to not be the case.

Pulling one fuse, and one relay at a time, with that multi meter connected and noting any change as you unplug things, is the next step.

IF the car has an aftermarket alarm/imobiliser, that would be my first port of call, if not, forget this suggestion.

If there is a "new" stereo recently fitted, check it out as a suspect item also.

I am still at a loss as to the spluttering at a set temp.

Just thought of something whilst typing, unplug the 2 connectors to the instrument panel, check that meter, did anything change??.

I reckon the engine will still start with that binnacle unplugged???, connect the battery "normally" see if that spluttering still occurs without instruments in the circuit. I may be wrong here, never tried my X300, but the XJ-S is no issues without instruments plugged in.

 

I have addressed a couple of things you suggested Grant.

1. It will run without the binnacle. It does NOT stop the car from dying out.

2. I unplugged the fuse for the sunroof which was not working properly. That didn't help.

3. Im waiting now to see if the battery drains with the car off again.

4. I did fix that problem where the car lingered to run after the ignition was off. It was the RH side ignition relay in the fuse box. It was sticking closed. It apparently was causing the P1777 code as well (That may have been the battery draw too.)

OH, and I have been meaning to tell you that there is not an aftermarket security system installed. It's all basic. The stereo is aftermarket, but it was worked well for two years and one of my first attempts at fixing this problem was to completely unhook that stereo, to no effect.

The problem remains that the binnacle/speedo cluster flashes at about the point where the coolant reaches 170 or so. After a little while of the cluster flashing off and on the car eventually dies out if sitting still. I have hunted and cleaned as many ground points as I can find. They were not corroded or anything, just a little road dust.


Back to the drawing board.

 

OK, outside of square thinking here, so look out.

The main thing in that binnacle that could cause that is the Tacho. It is basically counting revs from a signal derived from the low tention side of the ignition circuit??, -ve terminal on a standard single coil car, NO IDEA on these technological marvels, sorry.

I say this due to others posts I have read somewhere about the tacho giving a reading whilst cranking, and if it dont give a reading the crank angle sensor is faulty.

Bugga, maybe your sensor is giving out at temp, ??????, maybe. That could answer the cutting out, but NOT the flashing of the binnacle.

My sensor died in the driveway, drove it in, spouse wanted to go out for tea, as they do, NO GO, damn, took the XJ-S, and nothing made sense, but a new sensor fixed it, still not convinced, but it runs. Mine was at 165k kms, and rumour has it that these sensors fail at about 160k kms, for no known reason.

 

Grant, I reread my post from before. Removing the Binnacle does NOT keep the car from dying out, I just can't see the symptoms coming on because the gauges aren't there.

xjrguy, the white relay is still affixed to the bumper behind the plastic under the fron't bumper. I can see it. Those other connectors on the RH are clean as well.

What would the empty relay be on the RH side in front of the fuse box next to the washer fluid bottle neck? I opened one of those relays to check it for cleanliness and there was no relay there, just an empty cap.

Im going to check out the tach sensor, thanks Grant.

 

The phantom relay is probably the spot for a headlamp washer relay, which you probably do not have. I'm still stewing on the rest.

Cheers,

 

I repackaged this question under a new title concerning loss of ignition power. I did it because I think the flashing binnacle is entirely tangential to the main issue. The same thing that is causing the engine to die is the same thing that is causing a loss of power to the binnacle, they always happen at the same time, so I don't think it is a leap that they are connected, hopefully???

Take a look at how I have repackaged the question and the things I have done and let me know guys. I'm still without my daily driver and this is making things hard.

Thanks to Grant and xjrguy for following this!

 

Was there any resolution to this? I am in the beginning stages of what you described here. Car stalled twice in 10 minutes while at idle and in gear (left turn, and one stop light). After this on the same day the instrument panel lost power twice for only a second or two. This is day four and the instrument panel seems to be losing power quite regularly, and each time it does all the warning and caution lights stay illuminated for a few seconds. About half the time the SRS Airbag light will stay lit after all the other lights turn off, and instead of my current mileage the lcd display shows "airbag".

Advanced appologies if i'm not supposed to reply to such an old post but it is the only one i could find that seemed pertinent to my situation. Any help here is greatly appreciated. Thank you.

-Mike

 

Welcome Mike!

You didn't happen to replace any of your ignition coils within the last year or so did you?

I started this thread and then repackaged it under another title when I realized that it wasn't really a speedometer issue but it was an ignition issue.

I had the exact same start to my problem as you, and it only increased in severity and regularity.

My problem was that 4 of my 6 ignition coils were backfiring into the ignition system temporarily deadening everything. The cluster would flash just as you described.

Basically what was happening, the coils were sending some spark into the sparkplugs and and the rest back up the line. I fixed my problem as soon as I put my old Lucas coils back into the car. I used the new boots and the old coil bodies and she runs like the cat she is.

Message me back if this did not make sense.

 

Awesome Jack!! This absolutely makes sense. I just purchased this car and I believe they did a tune up on it right before I took it home. Thanks again, I will change the coils out as soon as I get a chance.

 

Oh just when it was just getting real interesting.
Please ,please, please was the coil packs the problem?
I have had the same issues :dash lights flashing,crazey shifting and stalling.
Same code p1777 . Runs for about 30 mins then crazytown.
I too have just replaced coil packs (with cheapies)
I would be very interested if changing the coil packs fixed you Jag.

 

YEah, it was. Jack started a new thread...I forgot the title. Have a look for threads started by Jack J and it'll probably pop out at you.


You're in luck...bout to turn in and stumbled on it:

See post #15 from Motorcarman in this one:

Loss of Ignition Power

also:

Instrument cluster flickers

 

aholbro1
Thanks , Jack emailed me direct and confirmed it was the coils.
Very helpful people in this forum. Thanks

 

Thanks for the update, kudos to aholbro too

Happy driving