Peaklander Posted November 10, 2016 Share Posted November 10, 2016 (edited) I know the problem is that the truck won't start properly but we have to get to the bottom of the voltage measurement. I have had a little look around and there are people reporting that when measuring direct current (DC) such as car battery voltages such as yours, if the multimeter is inadvertently set to the alternating current (AC) range, the measured voltage is double what is expected. It appears to be on cheaper models. The meter that appears below is the one in page 1 of this thread. The DC measurement ranges are those between 12 o'clock and 3 o'clock on the selector where the V symbol has the two straight lines next to it (indicating Volts DC). This is the range to use for voltage measurement on your Land Rover and you would normally select the appropriate range which would be 20, rather than 200 which might not give quite the precision you need, or 2000m which is 2000 millivolts - a maximum of 2V which you would use to more precisely measure smaller voltages. The AC ranges are the selector switch positions next to V~ between 4 o'clock and 5 o'clock, where you can select either 500 VAC or 200 VAC So.... are you measuring using the AC range? That's the question!! Also when measuring voltages, the red lead should be connected to the middle terminal (V Ω mA) and the black to the COM terminal on the right. The annotation on that drawing is not correct! Edited November 10, 2016 by Peaklander Added detail of lead connections Quote Link to comment Share on other sites More sharing options...
monkie Posted November 10, 2016 Share Posted November 10, 2016 (edited) I have tried to draw a simplified circuit diagram for you to help you identify where to take your measurements when the volt meter is sorted as above. As you can see, there isn't much to it. If you get a 12v reading from the starter motor terminal, at the ignition switch and then at the main feed when the key is held in the cold start position then the problem must be with the glow plugs. As recommended higher up, do a resistance test on all 4 plugs to see if they are all in agreement. If so, make sure there is a good earth to the engine block by connecting a jump lead from the negative terminal on the battery to one of the lifting eyes fitted to the engine. (all though I would have thought the starter motor wouldn't work if that is the case - but worth a try anyway I think). Edited November 10, 2016 by monkie To add picture Quote Link to comment Share on other sites More sharing options...
monkie Posted November 10, 2016 Share Posted November 10, 2016 Also, Trailerfitters videos on youtube are very good. Here is one on glowplugs. It is a 300tdi engine rather than the 2.5NA so the glowplugs are of a different type, but the principals shown are the same. Watch from 8:36 onwards. Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 10, 2016 Author Share Posted November 10, 2016 Fair cop Peaklander, I had it on the wrong setting- although it's worth noting that I followed the instructions, the person I'm not that keen on. Anyway I'll check everything tomorrow again, including resistance. Thanks for the info monkie, good to see the video. Was wondering if my glowplugs being dry was a good thing so glad I know now. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 10, 2016 Share Posted November 10, 2016 Great to hear there's a rational explanation. Let's hope the correct readings give an indication of the real problem you are trying to fix. Good luck! Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 10, 2016 Author Share Posted November 10, 2016 Cheers Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 11, 2016 Author Share Posted November 11, 2016 Hi chaps. Rechecked everything today and the results were: Resistance = 1.9-2.8 at for each plug (the meter was mostly stable on 2.8 but was jumping around a bit) Voltage= 12v at the battery, 10.8 v at each plug. So some power is being lost somewhere but not enough to interfere with plug function I would have thought. So what do we think? Cheers Quote Link to comment Share on other sites More sharing options...
Kevm Posted November 11, 2016 Share Posted November 11, 2016 The resistance through the plugs is on the high side but they are all working and I don't think a new set would make much difference. 10.8v is fine if you have the plugs connected as they will be drawing power. I think there is nothing wrong with your glowplugs now and if it won't start or is reluctant then you need to start investigating the fuel system and lastly (and maybe the cause of your problems) the head gasket. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 11, 2016 Share Posted November 11, 2016 (edited) The plugs will pull a fair amount of current (12v divided by 1.9 ohms is 6 amps each), so while they are on and heating, the battery will be working hard and might pull below its maximum which should be 12.8v if it is fully charged. If that measurement of 12v at the battery is measured at the same time as they are pulling current, then there is a bad contact in the circuit to the plugs because you shouldn't lose 1.2 volts. However I don't know the performance loss of the plugs operating at 10.8v rather than 12v, it's probably not that much and they will still heat. Someone else will be able to confirm that this isn't your starting issue. Edit: Sorry posted at same time as Kevm Edited November 11, 2016 by Peaklander Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 11, 2016 Author Share Posted November 11, 2016 Basically, it's nothing good would you recommend a garage as my next stop? I'm sure that will be nice and cheap... On an unrelated note does anyone have any experience of selling a kidney in Switzerland? Oh, the 12v (was actually 12.6) measured from the battery was with the glow plugs not on just to clarify. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 11, 2016 Share Posted November 11, 2016 I have a mate in Les Gets with Land Rovers. He might know someone nearer you - where are you exactly? PM if you want and I will text him with the question. However there's load of people on here who can help you work out what's gone wrong, now we know the glowplugs aren't the cause. How about starting again? It used to start on the button and now it won't start at all?? Did it happen suddenly and what had happened with the vehicle just before it failed to start? Quote Link to comment Share on other sites More sharing options...
western Posted November 11, 2016 Share Posted November 11, 2016 on the ignition switch make sure the thickest brown with red trace wire has a 12v feed & it is on terminal number 1. There is no fuse as its fed direct from battery, check battery end of that thick wire has a secure clean connection as well. Quote Link to comment Share on other sites More sharing options...
monkie Posted November 12, 2016 Share Posted November 12, 2016 I still think that there is a problem with the glowplugs/circuit some where because in your original post you say that the warning lamp isn't coming on. That needs addressing before you go down the route of head gaskets and other things. As Western says, make sure all the connections are good with no corrosion. Do you get 12v at the lamp with the bulb removed? Also in my experience the quality of the glow plugs makes all the difference. I once fitted cheap ones and they were no good from new making starting difficult. Beru plugs are what I use now and they are great. Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 13, 2016 Author Share Posted November 13, 2016 Hi all. Peaklander- i'll drop you a message in a mo, cheers. Western- yes I have 12v on the thick brown cable and it is on position 1. Haven't checked if it drops slightly when the plugs are heating (as suggested it might do above) but I'm getting good voltage to the plugs which I guess rules out a wiring issue from the battery no? Monkie- I agree still something must be wrong with the plugs as when the problem first started if the engine was warm it would restart no problem. Interestingly the bulb lights and the plugs get power when I put the glow plug wire on a different terminal on the ignition switch. But the intended position for the glow plug wire has power when the key is in the hold position so that's strange. Interesting re. plug quality but they always have been fine so I don't understand why that would have changed? Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 13, 2016 Author Share Posted November 13, 2016 I thought it might be useful to give the full story in fact. So here goes. Everything is working fine in the UK before I started my drive over to Geneva, very very difficult to start the old girl unless the plugs were heated, in fact more often than not the battery would die before it started, but 20secs of heating the plugs and it started first turn. Drive to folkstone everything still all good, get off in Calais all still good, drive a further 300km and stop for the night. Next morning I get in and turn the key to plug heat position but no warning light comes on and I have a lot of difficulty starting it but manage in the end and made it to my destination. Was pretty smokey for the last 20km so checked oil level and it had managed to use a lot and was on the min level so I topped up. The next day tried to start it but there was obviously an issue- plug warning light still not coming on and very tough to start. So I started this thread, changed the ignition switch and the light was working, plugs were getting power, plugs are working ex situ at least but still can't start the truck. Had it running once since then but took a long long time but sounded fine when it was up and running. And that brings us to where we are now. Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 13, 2016 Share Posted November 13, 2016 Got your PM and been in touch but his only known trusted garage is in Chamonix so nbg I'm sorry to say. Quote Link to comment Share on other sites More sharing options...
monkie Posted November 13, 2016 Share Posted November 13, 2016 20 seconds of heat is alot unless it is very cold. Before you throw the towel in I would make darn sure the connections to and from the ignition switch are clean and good and try a set of these. About 10 seconds of heat in the UK on a frosty morning gets my TD started on the first turn: https://www.amazon.co.uk/BERU-GV602-Older-Generation-Glow/dp/B0068M68Z0 The really made all the difference to cold starts and that was before I rebuilt the engine! Quote Link to comment Share on other sites More sharing options...
Kevm Posted November 13, 2016 Share Posted November 13, 2016 Sheathy, From what you have described, I think you had two faults, a slowly getting worse head gasket problem and then a sudden failure of the ign switch/glow plugs, sounds like you have fixed the glow plugs but your head gasket isn't getting any better. It should start better than that even without the glow plugs. I heat mine for 5/10sec and it then starts straight away, if I don't heat it at all it cranks for 10 or so secs then starts but is rough and smoky for a while. It is far easier to start since I did the head gasket, reseated valves etc. Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 21, 2016 Author Share Posted November 21, 2016 She is back on the road. I gave in and had a garage take a look at her, turns out the solenoid needed replacing and there were some other issues with the ignition switch wiring. Working well now though- only one small problem, I seem to be getting a battery drain when the car is left over night. It's not a battery issue as the battery is only a couple of months old. Also not the alternator as it's charging up fine. Cheers again for all your help. Quote Link to comment Share on other sites More sharing options...
monkie Posted November 21, 2016 Share Posted November 21, 2016 Glad you have got it all sorted in the end. Now you have an earth fault your money was certainly well spent on a multimeter. Good luck! Quote Link to comment Share on other sites More sharing options...
Peaklander Posted November 21, 2016 Share Posted November 21, 2016 Hi What sort of volts do you see 10 mins after you stop driving and what's the reading the next morning? Plus where are you measuring? Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 27, 2016 Author Share Posted November 27, 2016 Haven't actually had chance to measure the voltage but the battery was drained when I went to start. However I put the spare in (wasn't fully charged) and drove around for a couple of days with lights on etc yesterday stopped after an hour of driving, was out the car for a few minutes went to start again and it wouldn't even turn over so think it must be the alternator... Put in the other battery (now charged) and started fine. Quote Link to comment Share on other sites More sharing options...
monkie Posted November 27, 2016 Share Posted November 27, 2016 Has it started doing this since you took it to the garage to sort out your glow plug problem? If so, I would take it back to the garage and get them to sort it out FOC,it may well be that they have disturbed or damaged something perhaps. Quote Link to comment Share on other sites More sharing options...
sheathy Posted November 27, 2016 Author Share Posted November 27, 2016 Yeah i suppose it has, although i think i may have had a bit of an issue before but is much more obvious now Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted August 25, 2019 Share Posted August 25, 2019 An old thread, I know, and I came across it while searching for some glow plug info, but it's most frustrating when a thread is left unfinished!!! I know the original problem was with glow plugs, and it seems to have been sorted, but what were the cause and cure for your failing battery? Mike Quote Link to comment Share on other sites More sharing options...
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