Disco 2 Fuel gauge .

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Interceptorxj

Interceptorxj

Well-Known Member
Posts
1,723
Location
Bolton, Greater Manchester.
When I fitted a none genuine new fuel pump last year the fuel gauge stopped working properly, with it showing 1/4 full when full etc. I think I must have been sent a Defender one instead of Disco but it was too late to send it back as I had fitted it. "Parts need to be checked before fitment to be returned" .
Anyway after several times of trial and error I played about with the float arm and got it to read empty when empty and half full when full and have used it like this since coupled with the orange low warning light.
More recently the fuel gauge stopped working altogether & the low fuel orange warning light was on all the time so I assumed the pump sender or arm had failed altogether and I have been using the odometer to fill up every 450 miles without issue since. This week I decided to fix the problem by fitting a genuine fuel pump but much to my disappointment it hasn't cured the issue so assume the actual fuel gauge in the dash pod is the fault. Has anybody else had a similar issue and can confirm the gauge might be the problem?
 
Might be a fault in the instrument pack or a wiring issue too, as first test would be to go to C0378/0392(attached) and put a bridge with a paperclip across pins 12 - 13(pink/black - green/black wires), put the bridge then turn on ignition just for short time and if the gauge jumps to the top turn ignition off and remove the bridge but at least the intrument is ruled out then you can do the bridge at the pump's plug(same colour wires) ... according to the results we'll speak again

C0392.jpg
 
Thank you sierrafery, I disconnected the plug and linked it as per my photo, I turned the ignition on and the fuel gauge went up to full before dropping straight back down again whilst still linked?
IMG_1597.JPG
 
doesnt it do the same when you turn ignition on without the bridge and plug reconnected? if not put the bridge at the fuel pump plug and see then
 
Last edited:
No without the bridge and the plug reconnected looking carefully there is an initial flicker (it rises 1-2mm) when the ignition is switched on before it goes back down. The exact same when I bridge the tank end?
 
It seems that it's a wiring issue between the tank plug and the grey connector then, the fact that with bridge in the grey connector it goes all the way up is a sign of that, the real test would be if you wire somehow the old sender into the grey plug into those pins where the bridge was inserted, turn ignition on and move the float both ways or get hold of a resistor between 15 - 50 ohm and use it instead of the bridge cos with the bridge the resistance being 0 it's possible that the instrument goes into some protection mode against short circuit after it goes up first... the resistance of the sender element at full tank is 15 ohm that's why then at around 160 the warning is supposed to come on
 
It would appear you are correct sierrafery, I looked at the immediate wiring near the tank and couldn't see anything obvious so I tried another instrument binnacle just to rule out the gauge itself as this seamed the easier option than checking the entire length of the wiring. Unfortunately the other binnacle gave exactly the same results and I now have the added problem that my odometer is flashing. Can you please advise me how to reset this as I thought it would be ok once I plugged the old binacle back in with the same mileage as the BCU?
 
Was the other IP which you used for test with higher mileage than your original? ...if yes and you turned on the ignition few times then BCU might have sync'd itself automaticaly to it and now the mileage stored in the BCU is different than the one in your original cluster ... all you have to do is to go with tester into the BCU settings and disabe the odometer error warning
 
Thank you for taking the time to reply.

The other unit actually had lower mileage so I assume it is just because I unplugged it perhaps? I don't actually own a tester either but perhaps it's time I did. I've owned 6 TD5 LRs (4 Defender , 2 Disco) and have luckily never needed to use one despite doing all my own repairs and maintenance. Which tester is the next question.
 
Interceptorxj said:
Which tester is the next question.
Click to expand...
the ''smartest" and most versatile from all is nanocom, it's not cheap and covers only one model for the basic price but it has some well known glitches , next on the list at very close price which is not so smart but 100% reliable is hawkeye, the singe vehicle version became obsolete and not they sell the "total" which covers most LR modells... for a lower price there is Foxwell NT520 Land Rover also multiple modell coverage which works well but with less features than hawkeye ... i can't recommend other which is reliable with the Td5 engine at this time
 
sierrafery said:
the ''smartest" and most versatile from all is nanocom, it's not cheap and covers only one model for the basic price but it has some well known glitches , next on the list at very close price which is not so smart but 100% reliable is hawkeye, the singe vehicle version became obsolete and not they sell the "total" which covers most LR modells... for a lower price there is Foxwell NT520 Land Rover also multiple modell coverage which works well but with less features than hawkeye ... i can't recommend other which is reliable with the Td5 engine at this time
Click to expand...

Morning Sierrafery, this is really interesting I was looking to get a tester for bleeding ABS unit etc and also having at the moment intermittent issue with M + S lights and looking at your threads and advice to others on this it is best to check codes before laying the money out for a new XYZ Switch!! so based on the Hawkeye being 100 % reliable I am sort of leaning towards it would that tell me what the codes are? I am not tech minded o_O and complete novice to mechanics looks like the Hawkeye might be a good all rounder to get started with.
 
FIX UPDATE:

I have finally got round to fixing this problem. When I did a continuity test on both the green/black & pink black fuel sender wires from the pump end to the grey connector in the engine compartment fuse box they were both broken. I unwrapped the wiring loom from the engine bay down as far as I could in the inner wing to the chassis and couldn't find the break so decided the best option rather than try and take the complete wiring loom out front to back was to run two new wires in a separate protective sleeve which I cable tied to the existing loom before cutting the wires at the tank end and fuse box end and soldering the new wires in place. I now have both working fuel sender and low fuel light.
Many thanks sierrafery for your invaluable assistance.
 
I have the new lynx evo from Britpart it's ok I find it's cheaper than everything else and it's done everything I need it to worth a look if your on a budget
 
I have the new lynx evo from Britpart it's ok I find it's cheaper than everything else and it's done everything I need it to worth a look if your on a budget
 
You must log in or register to reply here.

Similar threads

A
Fuel gauge and fuel light issue
Replies
9
Views
655
Acdadefender1
A
mad85
Disco 2 TD5 Low Fuel pressure!!
2
Replies
22
Views
927
mad85
mad85
StuRox
Disco 1 Problem with Fuel Gauge - 300 Tdi
Replies
4
Views
662
StuRox
StuRox
D
Disco 2 td5 fuel purging doesn't work?
Replies
10
Views
703
Kev12
Kev12
mad85
Disco 2 best place for fuel pressure sender on td5
Replies
10
Views
1K
MJI
MJI
Back
Top