Odd electrical drain problem

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westone

Active Member
Posts
415
Location
West country
On my Discovery normal drain has been below 50milliamps.

While replacing a leaking oil filter I checked the battery and was surprised it was low at 11.5 volts, so checked the drain with a clamp meter and it was 0.4amps.

Then discovered it was only the 0.4amps up until the 1st earth point when it leaves the battery, please see picture.Its this figure to the right of the flat connector bolted down to the chassis and another wire is connected here and i think from looking at the wiring diagram this is the SLS system.
SLS seems to be working normal.Double checked with a multimeter in line and drain was same.

This area has 3 earth points on a bit of chassis rail.

On the other side of this flat connector( L.H looking at picture) the drain is 0.02amps which is about right for my Disco.

I spent a long time checking wires i could find underneath and under bonnet for any drain and found none.The cold got the better of me after 2 hours of this.

I am stumped as to why current drain goes to this point, yet beyond it returns to normal.

Any help would be much appreciated.I thought about disconnecting the earth point completely where this happens .Probably not a good idea.?

1892ABCE-FEA3-472F-90C1-A96FB74F1E89.jpeg
 
westone said:
On my Discovery normal drain has been below 50milliamps.
While replacing a leaking oil filter I checked the battery and was surprised it was low at 11.5 volts, so checked the drain with a clamp meter and it was 0.4amps.

Then discovered it was only the 0.4amps up until the 1st earth point when it leaves the battery, please see picture.Its this figure to the right of the flat connector bolted down to the chassis and another wire is connected here and i think from looking at the wiring diagram this is the SLS system.
SLS seems to be working normal.Double checked with a multimeter in line and drain was same.

This area has 3 earth points on a bit of chassis rail.

On the other side of this flat connector( L.H looking at picture) the drain is 0.02amps which is about right for my Disco.

I spent a long time checking wires i could find underneath and under bonnet for any drain and found none.The cold got the better of me after 2 hours of this.

I am stumped as to why current drain goes to this point, yet beyond it returns to normal.

Any help would be much appreciated.I thought about disconnecting the earth point completely where this happens .Probably not a good idea.?

View attachment 253265
Click to expand...
For between 30 and 90 minutes after switching off the engine or opening a door the SLS remains active drawing about 300mA. You can hear the SLS block "ticking" if you put your ear right on the SLS block.

My 2004 Landmark draws 16mA locked without the volumetric sensors on after this time.

You may not have an issue, but a "feature"!

PP
 
PopPops said:
For between 30 and 90 minutes after switching off the engine or opening a door the SLS remains active drawing about 300mA. You can hear the SLS block "ticking" if you put your ear right on the SLS block.

My 2004 Landmark draws 16mA locked without the volumetric sensors on after this time.

You may not have an issue, but a "feature"!

PP
Click to expand...
D'you fink ee's got a deadish batry or just hain't drivin it enuff?
 
Stanleysteamer said:
D'you fink ee's got a deadish batry or just hain't drivin it enuff?
Click to expand...
12V is considered completely discharged so, if the voltage was measured at the battery terminals, either the multimeter is inaccurate or the battery is completely dead, certainly not good enough to start the car. It is a bit temperature dependant, the lower the temperature, the lower the voltage, but not by that much!
 
PopPops said:
12V is considered completely discharged so, if the voltage was measured at the battery terminals, either the multimeter is inaccurate or the battery is completely dead, certainly not good enough to start the car. It is a bit temperature dependant, the lower the temperature, the lower the voltage, but not by that much!
Click to expand...
Twas what I was thinking. 12.6 volts when key off to be fully charged.
 
PopPops said:
For between 30 and 90 minutes after switching off the engine or opening a door the SLS remains active drawing about 300mA. You can hear the SLS block "ticking" if you put your ear right on the SLS block.

My 2004 Landmark draws 16mA locked without the volumetric sensors on after this time.

You may not have an issue, but a "feature"!

PP
Click to expand...
Thank you PP,
The disco had been sat for days, locked up a sleep so do not think thats it.I do not have any volumetric sensors.
The SLS seems to work fine, but I think If I isolate it this may reveal if its the culprit.I can pull a fusible link.The fuse controls ABS as well so cannot do that.
If not i can do it in Nanocom I think.
 
westone said:
Thank you PP,
The disco had been sat for days, locked up a sleep so do not think thats it.I do not have any volumetric sensors.
The SLS seems to work fine, but I think If I isolate it this may reveal if its the culprit.I can pull a fusible link.The fuse controls ABS as well so cannot do that.
If not i can do it in Nanocom I think.
Click to expand...
Don't be worried about pulling the fuse that controls the ABS. You can still drive the car without it. You just have to drive it like we all did before ABS was invented. Don't put yourself in a situation where you might skid and if you do, well clutch down, steer into the skid and pump the brakes!!!
I don't know if they still run skid pan training courses. I loved mine!!!
 
westone said:
I am stumped as to why current drain goes to this point, yet beyond it returns to normal.

Any help would be much appreciated.I thought about disconnecting the earth point completely where this happens .Probably not a good idea.?
Click to expand...
First of all with a clamp meter you have to measure around the battery positive lead, what you are doing on the earth leads is completely irrelevant.. and NO, dont ever disconnect a vehicle earth while the battery is connected
 
westone said:
Thank you PP,
The disco had been sat for days, locked up a sleep so do not think thats it.I do not have any volumetric sensors.
The SLS seems to work fine, but I think If I isolate it this may reveal if its the culprit.I can pull a fusible link.The fuse controls ABS as well so cannot do that.
If not i can do it in Nanocom I think.
Click to expand...
My car has been converted to coils at some time in the past, SLABS has been set to "coils", but SLABS is still active for the 30/90 minutes, so I'm not sure what you can do with the Nanocom.

You can check the current drawn by the SLABS by measuring the voltage across F11 in the engine fuse box. "Active" there should be about 0.7mV across the fuse, after 90 minutes of no ignition/door opening, nothing measurable. the relevant bit from the workshop manual is:

The SLABS ECU receives a continuous battery supply from fuse 11 in the engine compartment fusebox. An ignition
'ON' signal is supplied from the ignition switch via fuse 28 in the passenger compartment fusebox. The ECU has the
ability to control when it requires power and is not reliant on the ignition signal for it to power up.

The ECU incorporates a counter which times the operation of the SLS system and prevents the compressor
exceeding its duty cycle. The ECU can remain powered for up to 1.5 hours after ignition off is sensed to allow the
counter to continue running to avoid an ignition cycle resetting the counter.

Opening any of the doors will power up the ECU, irrespective of ignition switch position. The door open signal is
sensed by the door switch completing an earth path which is sensed by the ECU. The ECU cannot differentiate
between any of the doors. The door open signal powers the ECU for up to 30 minutes to allow the vehicle to re-level
when a load is removed or passengers leave the vehicle.
 
The straight way is to let the clamp meter on the positive lead then start pulling fusible links(FL) one by one, once the drain drops hard you know the main circuit which contains the draw, check the power distribution diagram which fuses are linked to that FL put it back and pull the related fuses one by one and when the drain drops you know the exact circuit for further troubleshooting or it can be something common... if you are not good with diagrams report back which FLs removal reduces the drain and i'll tell you more
 
sierrafery said:
The straight way is to let the clamp meter on the positive lead then start pulling fusible links(FL) one by one, once the drain drops hard you know the main circuit which contains the draw, check the power distribution diagram which fuses are linked to that FL put it back and pull the related fuses one by one and when the drain drops you know the exact circuit for further troubleshooting or it can be something common... if you are not good with diagrams report back which FLs removal reduces the drain and i'll tell you more
Click to expand...


Thank you very much.I will do this and report back and leave the earth connected. I appreciate your help...thank you.
 
PopPops said:
My car has been converted to coils at some time in the past, SLABS has been set to "coils", but SLABS is still active for the 30/90 minutes, so I'm not sure what you can do with the Nanocom.

You can check the current drawn by the SLABS by measuring the voltage across F11 in the engine fuse box. "Active" there should be about 0.7mV across the fuse, after 90 minutes of no ignition/door opening, nothing measurable. the relevant bit from the workshop manual is:

The SLABS ECU receives a continuous battery supply from fuse 11 in the engine compartment fusebox. An ignition
'ON' signal is supplied from the ignition switch via fuse 28 in the passenger compartment fusebox. The ECU has the
ability to control when it requires power and is not reliant on the ignition signal for it to power up.

The ECU incorporates a counter which times the operation of the SLS system and prevents the compressor
exceeding its duty cycle. The ECU can remain powered for up to 1.5 hours after ignition off is sensed to allow the
counter to continue running to avoid an ignition cycle resetting the counter.

Opening any of the doors will power up the ECU, irrespective of ignition switch position. The door open signal is
sensed by the door switch completing an earth path which is sensed by the ECU. The ECU cannot differentiate
between any of the doors. The door open signal powers the ECU for up to 30 minutes to allow the vehicle to re-level
when a load is removed or passengers leave the vehicle.
Click to expand...

Thank you PP bit more to test for.....I had this problem before 18 months ago and fixed it.Cannot recall how.I think it was when I rebuilt the compressor ,replaced relay 5 under bonnet and all fuses....now its come back to haunt me.!
It's a bit cold at the moment to do much on it so will wait a bit until the cold snap goes away.
 
westone said:
Thank you very much.I will do this and report back and leave the earth connected. I appreciate your help...thank you.
Click to expand...

Well braved the cold as long as I could using + terminal for my clamp meter drain same as negative lead which i would have expected.
I started pulling the fusible links one by one and when i got to a pink 30amp(F9) one the current dropped quickly to 0.03amps .With this in its 0.3amps.
So assume this is the one from the diagram its SLS sadly.

I pulled the relay out and it looked okay and replaced it with a spare ,I have the same one in my spares box a Ripco 2152, the one fitted has a C on it but was told by the supplier its the same same.The legend on the front looks the same for the contacts. Its not a Land Rover one is this okay?

In early 2020 when i bought Disco the air suspension did not work. So I fixed it work,I did most of the work myself including fixing the compressor, new height sensors and bags.I could not install the bags due to health issues, so a garage did that for me.They put this Ripco relay in as they said the old one was bust as well as the 30amp fuse.
They could not calibrate the system so I did this with Nanocom.

I do have a spare compressor in a Wabco box as I enjoyed fixing the 1st one, bought another one and mended it...tested with a 12v supply giving 4 bar output I think from memory.So could swap them if you think I should?

I checked air suspension would raise and lower correctly it does.

I looked at the system with Nanocom and it saye's no faults

I did notice really R6 is missing,I think this is for glow plugs and mine is a petrol version.

Now stuck on what to do.?
A49A53E5-D6B3-4C25-B951-5B3D4948B5BD.jpeg




Please see picture of the relay.
 
That relay is OK ...Was the SLS system "at sleep" when you measured? I mean was it more than 90 minutes since the ignition was off and did you wait more than 30 minutes after you opened a door? cos if these conditions were not met it's normal to have bigger drain on that circuit as @PopPops quoted with green.
 
Thank you for your reply.
Those conditions were met.I was very aware of making sure they were. It was 18 hours since Disco had been powered or any door openI.

do not have a bonnet switch for the alarm so that was not on.
 
westone said:
Well braved the cold as long as I could using + terminal for my clamp meter drain same as negative lead which i would have expected.
I started pulling the fusible links one by one and when i got to a pink 30amp(F9) one the current dropped quickly to 0.03amps .With this in its 0.3amps.
So assume this is the one from the diagram its SLS sadly.

I pulled the relay out and it looked okay and replaced it with a spare ,I have the same one in my spares box a Ripco 2152, the one fitted has a C on it but was told by the supplier its the same same.The legend on the front looks the same for the contacts. Its not a Land Rover one is this okay?

In early 2020 when i bought Disco the air suspension did not work. So I fixed it work,I did most of the work myself including fixing the compressor, new height sensors and bags.I could not install the bags due to health issues, so a garage did that for me.They put this Ripco relay in as they said the old one was bust as well as the 30amp fuse.
They could not calibrate the system so I did this with Nanocom.

I do have a spare compressor in a Wabco box as I enjoyed fixing the 1st one, bought another one and mended it...tested with a 12v supply giving 4 bar output I think from memory.So could swap them if you think I should?

I checked air suspension would raise and lower correctly it does.

I looked at the system with Nanocom and it saye's no faults

I did notice really R6 is missing,I think this is for glow plugs and mine is a petrol version.

Now stuck on what to do.?
View attachment 253325



Please see picture of the relay.
Click to expand...
Can you confirm F9? F9, from looking at my circuit diagram, is for the Heater-Fuel Burning, only.
 
westone said:
Thank you for your reply.
Those conditions were met.I was very aware of making sure they were. It was 18 hours since Disco had been powered or any door openI.

do not have a bonnet switch for the alarm so that was not on.
Click to expand...
Just confirm you let the bonnet opened 18 hours and didnt open any door before you measured?
 
westone said:
Thanks PP...It was called F9 I thought. It's the with one with from the left in my picture from the left 30amp(Fusible link).
Its newer than the 1st a sit was replaced 18 months ago....not sure what heater fuel burning is?...my Disco is a petrol.

See link below which shows the fuse boxes.

https://fusesdiagram.com/land-rover/fuses-and-relay-land-rover-discovery-2.html
Click to expand...
Ah, yes, cross purposes here! In the circuit diagram, what you are referring to as F9, is called "Link 9" which only feeds the compressor relay. If you leave F9 (Link 9) in and pull out the compressor relay, number 5, does the current also fall?

PP
 
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