Discovery td5 wont shut off

Hi all new to the thread and got a very strange problem. My discovery td5 wont turn off with the key can take it out and it keeps running. It all started when I changed the alternator. Changed the alternator not problem but I knocked the injector loom out so plugged it back in and never thought anything of it put it all back together and now doesn't turn off untill the brake is pressed or head lights put on then it turns off like normal. Also if I turn the key back on and off again quick it will turn off? Any help much appreciated thanks in advance.

First to be ruled out is a sticking ignition switch, when it happens again to turn ignition off and the engine keeps running unplug that C0028, the pic is from LHD vehicle but the plug is at the same place in the interior fusebox...if it stops then the ignition switch is sticking, if it doesnt stop we'll speak again

Hi thanks for your quick response and just been and checked now and no change still running when plug is disconnected thanks

then remove relay R9 and if it stops put R8(heated screen) instead for test and if this cures things put new relay, if no joy try to remove relay R2

Hi tried this morning and removed r9 and it turned off carnt try with r8 though as their isn't a relay there any advice on another relay I could try thanks

R6-glowplugs but dont use R9 instead anything untill is not ruled out which means the engine will not stop with R6 either...if it will stop normally with R6 then you'll have to buy a new relay(YWB101300)

Hi tried with r10 abs relay and no improvement. Checked red plug on ecm and was contaminated with oil, changed rocker gasket and injector loom and cleaned all plugs out tried and still no improvement.

Also unplugged fuel pump relay and it stayed running but car cut out when plugging it back in?

It's or a short to earth on the part of harness which connects the ECU to the fusebox, or a problem within the fusebox or the ECU is fubar'd cos as the main relay is not sticking it means it gets and earth path on the coil for some reason and stays closed after the ignition is off... undo the 3 bolts of the fusebox and jiggle it with every relay in place also squeeze the harness which comes into it and if it stops that's it.... if you have a multimeter and RAVE i'll tell you where to measure to see if the ECU sends the command or not

Hi Ithere does switch off when r9 is unplugged sorry but I put r10 in to check and doesn't fix problem but it does switch car off when r9 is removed thanks

I understood that and that's why i said that something keeps the coil of the main relay "armed" which means it gets an earth on the coil with ignition off as it has permannent feed one side and that's not supposed to happen, the ECU sends that earth but it can get there for other reasons too as i described in my previous post, to rule out the ECU remove fuse F1 and see if it stops then ... if it is the earth is sent by the ECU, if you have basic knowledge of electrics you'll understand from this diagram

is the oval 3way plug in the back of the alternator in the right way? they have 3 wires if that was the wrong way it can squirt 12v feed to the switched side of the ign switch so basic like keeping the key switched on however this is a very low current output so as soon as you load the system headlights wipers etc.... its enough to drop the voltage to make the relays drop out

Lee52 said:

is the oval 3way plug in the back of the alternator in the right way? they have 3 wires if that was the wrong way it can squirt 12v feed to the switched side of the ign switch so basic like keeping the key switched on however this is a very low current output so as soon as you load the system headlights wipers etc.... its enough to drop the voltage to make the relays drop out

Click to expand...

That's a very interesting theory.... can be correct but that means the diagram and connector view in RAVE are wrong cos according to those there are only 2 wires and 12V can go back only on pin 2 which is in the middle so no difference if the plug is reverted and if pin 1 misses the output the battery warning stays on... looking forward to see how this ends though cos it won't be the first time for RAVE to be wrong

Just an idea as the op said the problem happened after the alt change . I know the plugs are keyed to only go in one way but with enough force these things do (I see it daily at work on brand new plant equipment the assembly lads can make a square peg fit a round hole lol

Yes, and a very good ideea, that's why i didnt contradict it cos it's a possibility provided the diagram and connector view are wrong

The op didnt say if the replacement alt was new recon second hand etc.... Ive seen recon ones wired up wrong internally wasnt that long ago I got a recon starter motor and it span backwards lol. if the plug is it correct I would unplug the alternator and see if the disco shuts of when the key is turned of

Good point

Hi alternator was new from local auto parts shop carnt seem to get my hand to plug when it's installed space is quite restricted to try unplug it while it's running. Also now since I've changed injector harness and cleaned red plug out car seems to be stuck in limp mode but no warning lights are on? Becoming a real pain

If you unplugged the injector loom with the rocker cover on and replugged it it's possible that there's not good contact anymore cos the injector side plug must be kept against the other plug when you connect them or it can be pushed up and loose good connection, that's common and then the engine will not run 5 cylinders....this has nothing to do with the non-stopping issue but if the alternator failure was due to shot diode pack the ECU could have got some higher AC voltage spikes which and that can ruin it.

you dont have to unplug the alternator while the engine is running just to unplug it and make some start/stop tests to rule out what Lee52 said cos it's a good point

Hi all just been messing about with it took rocker cover back off and made sure plugs were all connected properly. Still no improvement with the limp mode. Also I managed to unplug the alternator any try and stop and starting the engine and it stops normally with alternator unplugged but as soon plug it back in the car won't turn off again is this then a dud alternator or could it be wiring fault causing both issues?