Jagalag, for your battery voltage to be "drifting" as far as it is (11.65 to 12.35) just by plugging in a code reader and maybe causing a computer or two to start up, that is telling me that you have a wire with a high resistance connection in it. Please keep in mind that when I say "high resistance", I am talking an ohm, maybe 2. I am not talking 100's or 1,000's of ohms. Now, this could also indicate that you have a cell that is starting to go in your battery. This is where a load test will eliminate the battery. If you get this done (free at most auto parts stores atleast here in the US), if you get back a reading of 75% capacity or less, the battery needs to be replaced. Low capacity batteries raise hell with X-Types.

I base this on a rule of thumb I have found that holds fairly true: for every 10 amps of current pulled from a battery, you will see a 0.1 VDC drop in the battery voltage. So, in your case, to see the battery go from 11.65 to 12.35 VDC, that is a 0.7 VDC change. So, that would mean you somehow got a 70 amp draw from the car without turning anything serious on except for maybe a computer or two. Not likely. That is why I question the wiring. This is where the battery cables are the most likely suspects, but have heard of a few people having issues with the starter terminal too. This is where undoing the connection, scrubbing it some with a wire brush to get back to a silvery(shiny) color is going to ensure you have a good connection. This is where doing the cupped hand test on the battery terminals is going to be another good test to do the next time you start the car (if you question how to do this, let me know). Kinda like the low voltage may be causing your loss of reception. Do things start working again when the voltage rises back up to 12.3+ VDC? Digital stuff can act really goofey if it gets too low/high of a voltage.

 

Thanks Thermo,
The battery itself is brand new, it's only had one serious journey on it (50 mile round trip, and a 20 and 10 mile trip before that), it was last on 12.54V, but it had a few door openings and some OBD and engineering tests done since it was parked up, but nothing extensive. If I remember roughly from earlier on there was about a 0.2A draw on opening the door with the courtesy lights coming on, so a relatively small voltage drop though. I probably closed the door afterwards. I did test the positive cable run from the alternator (through the starter) to the positive terminal on the battery before on several occasions and there was only 0.1 ohm measured, and the same voltage. I did the same via the negative battery terminal to the body of the alternator.
Also I did the cup test on the battery terminals some time back (about 2 months) with the old battery and no appreciable temperature rise was detected then. Do you think it's still necessary to remove the starter connector and clean it if the tests aren't indicating an issue in the line?
When the voltage got back up to 12.35V, the day before yesterday the fob still did not work for the rest of the day (tested a couple of times) and yesterday until midnight when the alarm went off and the fob started working to lock the door etc. I did not test the voltage then but only presumed it had remained around 12.35V. I tested today twice and it had stopped working again.
As I have not really been driving the car it hasn't been getting charged up regularly though it was 12.54V a week back - but you might need to read back over my past few posts I think to get the idea of what has been happening there

 

Jagalag, taking it apart just because I would not be practical. Now, I would say if you can get your hands on a IR thermometer and can get the temp of the connection, then anything above say 15F (10C) above the surrounding metal temps, then yes, a cleaning would be called for.

The other trick you can try is sliding the black post into the positive battery terminal to make it stay there. Then start up the car, put on a decent load (seat heaters, front/rear defrost on high, headlights). Then use the red multimeter lead and touch the bolt of the starter main connection (the one that goes to the battery and the starter). If you can get over say a 0.5 VDC indication on the multimeter doing this, then cleaning that connection would be in order too.

 

Yes I do have IR thermometer as it happens so I can use that to see if the temp is higher. I take it that I need to start the engine to produce a significant current draw?
Which black post are you referring to?

 

Black post = black lead of the multimeter. The red lead would go on the starter post.that has the battery cable.

 

OK thanks!
I did do an initial test, but it's near on impossible to find the starter positive post on a x-type diesel without removing several layers of gubbins from the top and I don't know how accessible it would be from the underside either, even if on jackstands. I tried to find as close to the positive post as poss but could see it with the laser pointer of the IR thermometer the temp reading with the engine running but not at load at that point of my investigation gave a temp in the end body and zone of the starter in keeping with the surrounding metal. I tested on the engine and positive and neg lead posts of the battery and their connectors and any exposed copper wire on the connection. Only the positive had a temp diff of about 2 deg C higher on the copper end than the post and connector (again it wasn't under full load at this point) - The central locking / other issues were still there at that point too. I then got the central locking to work again but the weird diagonal lock issue on FP and RD doors remained. That was 3 days ago.

Yesterday I cleaned the car and took my tools out of the boot etc as I was to pick up my wife, daughter and friend from their trip away at the nearest train station. I drove the car across the road to my house and left the engine running on idle for about 50 mins whilst I completed the cleaning. In the process I removed the spare tyre well tray and saw that the boot had a layer of water in the bottom into which a loose unplugged cable end was bathing; I think this is the none 'live' end of the disconnected parking sensor unit - which I had removed originally when I got the car as it was sitting in a significantly deeper pool of water and had corroded some of the SMT solder joints (I was going to resolder but unfortunately lost some of the tiny SM components). Anyway despite have recut the rubber drain plug splits for draining down boot water it obviously hasn't worked effectively about 2 yrs later. However I cleaned it up and widened the splits on the drain bungs again.
After I had completed everything I had had the cabled OBD tester on the whole time measuring battery charge, it had been showing a very fast cycling through of voltage from about 13.7 - 14.2 several times a second, I then ran through all the other features it had which were tbh fewer than my BT OBD, but possibly with some other 'better' options. Having done that and about to lock up the car suddenly decide to right itself all of a sudden and then everything was working again including the diagonal lock issue disappearing!
Then on driving off an hour later to pick up my family late last night, the highbeams went but the indicators carried on working!

 

It is possible that connector was getting went and that was putting a ground on the GEM module (or some other module), which in the end was messing wiht the locks and whatnot. I would say to keep that connector dry and see if your problem comes back. If not, then there is your cause. Now, getting water into the boot, that is a separate issue that should be taken care of.

As for the high beams, based on what you are describing, that is most likely a blown fuse for the high beams. If you replace the fuse and it blows again or does not fix the issue, then let me know

 

As this is my third attempt at posting my reply after my PC dumped my last 2 messages before I got to post them, this is the short version😒

In my last reply I wrote: ..'I tried to find as close to the positive post as poss but could see it with the laser pointer of the IR thermometer..' should read couldn't as I wasn't able to get an angle on it. Equally I don't think it was getting wet if the starter motor positive is the connector you are referring to being on the engine side in the middle of the bay; the car is stood unused most of the time and even the few journeys that I have made in the rain and puddles I would have thought that area would have dried out soon enough from the engine heat.

Just to follow on, the return journey from the train station the indicators stopped and started working a few times along the way, Another trip to the shops the following day (2 days back) saw every combination of the above issue come and go. The car fob has worked the past 2 days and voltage test via cabled OBD showed 12.6V, but the diagonal lock issue currently remains.
It turns out the fuse had blown ..as was the same issue 2 months back just before the 60A glowplug fuse blew from a short-out of its cable to negative earth. I have replaced and tested ok. The car has not been driven for 2 days
​​​​​​

 

Sounds like the high beams have a separate issue. This is where a good look most likely inside the headlight housing is going to show that you have 2 wires very close to each other that are touching periodically, blowing the fuse. Granted, could be a bad relay too. The easier thing is to replace the relay and then see if the fuse blows yet again. But, that may take a little bit of time.

As for the lock issue, this is getting a little interesting. Because it is also affecting your turn signal indicators, then this would seem to point back to your GEM module. I am not sure where to take things at this point other than to say replace the GEM module.

 

It official my car is possessed! I anticipated the GEM swap out and had ordered a secondhand one as cheap as I could get it. It arrived today. I had made a few more recent journeys and most things that were going weird continued to do so and then not, but generally they were. I added continuous and significant loss of power and presumably turbo going on so hill climbs where I was shooting up them are now slogs to get up especially with passengers; before it was just and occasional imposition now it's most of the time, I also had my start to work again on the last journey but no longer actioning the locks, so the indicators blink as they are supposed to and nothing happens.
So I chucked the replacement in and low and behold nothing happened, in fact it was worse than before as I'd lost my symbolic indicator flash via the fob😐 So it might be safe to say that it's probably not the GEM that's at fault unless I got a dud, I'm wondering if it could be a ground issue somewhere else - or the like - all the wiring and plugs around the GEM looked dry, intact and clean. Here's a couple of pics of the GEM I pulled out


Anyway beyond that when I got to the car there was a puddle of black watery stuff that seemed to have formed from the front corner of the car. Further examination revealed it dripping off the front undertray cover, but couldn't identify a source higher up - the main engine bay undertray is not on the car at the moment. The black stuff was not oily but more like a kind of washing of carbon black that may have emanated from a deposit on top of the front undertray. I got some on my hands and it was quite inky. see photos below. So I don't know if it is the wash off as such or coming from somewhere else. It had rushed onto the wheel when driving and sprayed up over the side of the car too.

Black inky leakage - middle pic of 3 in row shows a piece of paper soaked in the liquid
On reflection, and considering the drop in power I'm now thinking this may be related to burn-cycle 'washings' that may be coming through a 'tube' that has detached or split, such as the one to the intercooler - 1.5 year back I blanked off the EGR and fully cleaned out the clogged arteries of the intake manifold and associated chambers (after the car had cut-out and failed to restart on a couple of occasions)

 

I solved the inky black leak which turned out to be a snapped jubilee clip at the intercooler intake and I put on another jubilee clip (actually 2 joined together) and hopefully all is well.


I havent been able to yest it yet as the latest issue is that when I went to open the car the last time the alarm went off and I couldn't get the fob to cancel it like normal, so I pulled the neg terminal on the battery and any attempt to put the cable back on sets off the alarm.
So I might have to pull a fuse for it or something, or simply remedy the underlying issue😏

I have tested the resistance across the neg battery terminal and the car body/engine and it's about 0.9 ohm, similar to the pos batt terminal to fuse box. I checked the bolt on the main body ground in front of the fusebox too and that is solid and fully tight

 

So I went back over the resistance tests of the battery postive to fuse box and batt negative cables - and all checked out at about 0.7 to 0.9 ohms .Then I double-checked the batt neg to mount point on the body and only the bottom metal crimp had continuity at 0.9 ohms, the hex-head of the bolt which was rusty on the surface was open-circuit no matter the how much scratch to reveal metal I made on the surface.

So then I tried to undo the bolt, as I had before (but had done up as I met resistance after one or two turn), but there was resistance again and I wondered if it was either seized or had a nut on the other side that was binding it. However the otherside was behind a wheel arch liner and I couldn't be bothered to check it out so carried on and snapped the head off instead😏

Neg battery ground bolt and connector - quite rusty
So the rustiness of the bolt washer and deposits on the connector may have been enough to prevent conductivity across the bolt.
Anyway I spied another bolt nearby which was easy to undo however its built in washer was too wide for the connector. I cleaned the surfaces of the connectors up and found an alternative bolt and some washers to use instead.


All clamped down tightly and hoped for some improvement

but as soon as I put the final battery connector on the alarm went off again. Removed the horn fuse (F3 for a diesel) and then went and started the car up revved it up and took it for a very short ride up and down the street. The pickup is immense, shame the rest doesn't work! I'm wondering if the fully blanked EGR has created a bit more pressure through the system, pressurising the turbo circulation.

Then I did a heat test on the battery cables; initially they were cool with no added ancillary function, then I turned heater and fan full bore and headlights which were still not working properly (though the fuse is ok), with one main light and parkers on.
Initial voltage scross battery pretest was 12.77V, then 11.83V when systems switched on, some heat coming from postive terminal but easily touched and none from neg. Then started car and cupped terminals, neg relatively cold but pis started to warm up, but still touchable. Got IR temp gun and measured about 28 -40°C on top of connector and 60°C at top temp just below cable connector but could touch it still anyway. Initial running voltage was 12.2V for a short period then it rose to 13.98V

 

It's been a little while, but I have left the replacement GEM in the car, though I suspect at this point that the other one is possibly good and that the issue must lie elsewhere. However having made a number of (unroadworthied) journeys the car now reliably has indicators to use and most of the rest of the issues have not seemed to have cropped up with the exception of the central locking and alarm systems. Here the fob seems not to have consistently worked (except initially I think) and so I must open the car with the key, for some period now this sets that alarm system to engage with a quiet, constant, slow beep tone and I have to put the key in and turn it to at least position 'I' if not 'II' to switch it off and prevent the alarm going off if I open another door. The central locking is stuck in the diagonally opening mode (though I don't think the front passenger actions the rear driver at the moment but possibly the rear passenger - it's hard to keep tabs on) Either way locking up usually requires manual locking of all the doors internally - the boot can open once the driver's side central lock is activated, usually by closing and opening the lock (whilst the door is closed).

Otherwise the headlight issue is still there and is now definitely related to blown fuses, I've gone through 3 more and blow pretty quickly whilst moving once the main beams are switched on. However I have examined the connections at the bulbs on both sides and there does not appear to be any mechanism by which they would be short-circuiting there. One connector has rubber insulation and they are both suitably far apart from each other not to touch anyway and there's no metal part that I can see that is compromising the independent lines. So I would assume that there must be a short of sorts acting elsewhere (incidentally the replacement fuses break points are much thinner than the originals)

So that's where I'm at right now

 

Just to add that (with the key out) I pulled the fuse and tested the socket of Fuse 29 for the left side (passenger) headlamp against the +ve battery terminal and both sides gave me 12V - then I tested the resistance of both sides to ground and the were both 1.3 ohms, then I tested from the dip beam bulb positive connector (whose brown plastic housing I had put back on as it had come off a little while ago and I found it again) to the load side F29 and it was 0.7 ohms and to the (12V) supply side of F29 socket and it was 1.3 ohms - across the fuse socket pins it was 1.3 ohms again. It seems from this information that there must be some break in the supply side that is also shorting out to ground - it would seem to imply that this would be in the fuse box itself if it is on the supply side perhaps between it and including the relay, if it is only drawing current and powered when the dip headlamp is switched on. I will check the relay R11 next.

 

Yesterday I tested R11 relay socket in the fuse box and there was 12V seen across the batt +ve to connector pin 5, all 3 of the other connector pins were OC - there was 0.03V between connector pin 2 - 3. There was a 110 ohm resistance between 5 and 1, all other pin combinations were OC. The socket pin 5 was continuous circuit to the supply side and load side socket pin of F29 whilst F30 was still in, but once F30 was removed as well it became apparent that the current had been going through a 'circuit' created by F30 to the supply side of F29, since the load side lost its continuity on both F29 and F30 so registering as 12 V (OC). A resistance test across the supply side fuse sockets (F29 and F30) gave an expected 0.7 ohms, on the equivalent load side it was 1.4 ohms between them, seemingly indicating some small resistance in presumably the length of wiring and filaments but showing continuity through body ground
The relay itself had 91.5 ohms across the coil pins 1 - 2